Anisotropic conductive connector and probe member and wafer inspecting device and wafer inspecting method

ABSTRACT

An anisotropically conductive connector including elastic anisotropically conductive films each having a functional part, in which a plurality of conductive parts for connection containing conductive particles and extending in a thickness-wise direction of the film have been arranged in a state mutually insulated by an insulating part. Assuming that a thickness of the conductive parts for connection in the functional part of the elastic anisotropically conductive film is T1 and a thickness of the insulating part in the functional part is T2, a ratio (T2/T1) is at least 0.9

TECHNICAL FIELD

The present invention relates to an anisotropically conductive connectorsuitable for use in conducting electrical inspection of a plurality ofintegrated circuits formed on a wafer in a state of the wafer, a probemember equipped with this anisotropically conductive connector, a waferinspection apparatus equipped with this probe member, and a waferinspection method using this probe member, and particularly to ananisotropically conductive connector suitable for use in conductingelectrical inspection of integrated circuits, which are formed on awafer having a diameter of, for example, 8 inches or greater and have atleast 5,000 electrodes to be inspected in total, in a state of thewafer, a probe member equipped with this anisotropically conductiveconnector, a wafer inspection apparatus equipped with this probe member,and a wafer inspection method using this probe member.

BACKGROUND ART

In the production process of semiconductor integrated circuit devices,after a great number of integrated circuits are formed on a wafercomposed of, for example, silicon, a probe test for sorting defectiveintegrated circuits by inspecting basic electrical properties of each ofthese integrated circuits is generally conducted. This wafer is thencut, thereby forming semiconductor chips. Such semiconductor chips arecontained and sealed in respective proper packages. Each of the packagedsemiconductor integrated circuit devices is further subjected to aburn-in test for sorting semiconductor integrated circuit devices havinglatent defects by inspecting electrical properties under ahigh-temperature environment.

In such electrical inspection of integrated circuits, such as probe testor burn-in test, a probe member is in use for electrically connectingeach of electrodes to be inspected in an object of inspection to atester. As such a probe member, is known a member composed of a circuitboard for inspection, on which inspection electrodes have been formed inaccordance with a pattern corresponding to a pattern of electrodes to beinspected, and an anisotropically conductive elastomer sheet arranged onthis circuit board for inspection.

As such anisotropically conductive elastomer sheets, those of variousstructures have heretofore been known. For example, the following PriorArt. 1 discloses an anisotropically conductive elastomer sheet(hereinafter referred to as “dispersion type anisotropically conductiveelastomer sheet”) obtained by uniformly dispersing metal particles in anelastomer, and the following Prior Art. 2 discloses an anisotropicallyconductive elastomer sheet (hereinafter referred to as “unevendistribution type anisotropically conductive elastomer sheet”) obtainedby unevenly distributing particles of a conductive magnetic substance inan elastomer to form a great number of conductive parts extending in athickness-wise direction thereof and an insulating part for mutuallyinsulating them. Further, the following Prior Art. 3 discloses an unevendistribution type anisotropically conductive sheet with a difference inlevel defined between the surfaces of conductive parts and an insulatingpart.

In the uneven distribution type anisotropically conductive elastomersheet, since the conductive parts are formed in accordance with apattern corresponding to a pattern of electrodes to be inspected of anintegrated circuit to be inspected, it is advantageous compared with thedispersion type anisotropically conductive elastomer sheet in thatelectrical connection between electrodes can be achieved with highreliability even to an integrated circuit small in the arrangement pitchof electrodes to be inspected, i.e., center distance between adjacentelectrodes to be inspected. Among the uneven distribution typeanisotropically conductive elastomer sheets, that having conductiveparts formed in a state projected from the surface of an insulating partis advantageous in that high conductivity is attained with smallpressurizing force.

In such an uneven distribution type anisotropically conductive elastomersheet, it is necessary to hold and fix it in a particular positionalrelation to a circuit board for inspection and an object of inspectionin an electrically connecting operation to them.

The anisotropically conductive elastomer sheet is flexible and easy tobe deformed, and so it is low in handling property. In addition, withthe miniaturization or high-density wiring of electric products inrecent years, integrated circuit devices used therein tend to arrangeelectrodes at a high density as the number of electrodes increases, andthe arrangement pitch of the electrodes becomes smaller. Therefore, thepositioning and the holding and fixing of the uneven distribution typeanisotropically conductive elastomer sheet are becoming to be difficultupon its electrical connection to electrodes to be inspected of theobject of inspection.

In the burn-in test, there is a problem that even when the necessarypositioning, and holding and fixing of the uneven distribution typeanisotropically conductive elastomer sheet to an integrated circuitdevice has been realized once, positional deviation between conductiveparts of the uneven distribution type anisotropically conductiveelastomer sheet and electrodes to be inspected of the integrated circuitdevice occurs when they are subjected to thermal hysteresis bytemperature change, since a coefficient of thermal expansion is greatlydifferent between a material (for example, silicon) making up theintegrated circuit device that is the object of inspection, and amaterial (for example, silicone rubber) making up the unevendistribution type anisotropically conductive elastomer sheet, as aresult, the electrically connected state is changed, and thus the stablyconnected state is not retained.

In order to solve such a problem, an anisotropically conductiveconnector composed of a metal-made frame plate having an opening and ananisotropically conductive sheet arranged in the opening of this frameplate and supported at its peripheral edge by an opening edge about theframe plate has been proposed (see, for example, the following PriorArt. 4).

This anisotropically conductive connector is generally produced in thefollowing manner.

As illustrated in FIG. 31, a mold for molding an anisotropicallyconductive elastomer sheet composed of a top force 81 and a bottom force85 making a pair therewith are provided, a frame plate 90 having anopening 91 is arranged in alignment in this mold, and a molding materialwith conductive particles exhibiting magnetism dispersed in a polymericsubstance-forming material, which will become an elastic polymericsubstance by a curing treatment, is fed into a region including theopening 91 of the frame plate 90 and an opening edge thereabout to forma molding material layer 95. Here, the conductive particles P containedin the molding material layer 95 are in a state dispersed in the moldingmaterial layer 95.

In each of the top force 81 and bottom force 85 in the mold, a pluralityof ferromagnetic substance layers 83 or 87 are formed, on a base plate82 or 86 composed of, for example, a ferromagnetic substance, inaccordance with a pattern corresponding to a pattern of conductive partsof an anisotropically conductive elastomer sheet to be molded, andnon-magnetic substance layers 84 or 88 are formed at other potions thanthe portions at which the ferromagnetic substance layers 83 or 87 havebeen formed. A molding surface is formed by the ferromagnetic substancelayers 83 or 87 and the non-magnetic substance layers 84 or 88. Recessedparts 84a and 88a for forming projected parts on the anisotropicallyconductive elastomer sheet are formed in positions of the moldingsurfaces of the top force 81 and bottom force 85, at which theferromagnetic substance layers 83 and 87 are respectively located. Thetop force 81 and bottom force 85 are arranged in such a manner thattheir corresponding ferromagnetic substance layers 83 and 87 are opposedto each other.

A pair of, for example, electromagnets are then arranged on an uppersurface of the top force 81 and a lower surface of the bottom force 85,and the electromagnets are operated, thereby applying a magnetic fieldhaving higher intensity at portions between ferromagnetic substancelayers 83 of the top force 81 and their corresponding ferromagneticsubstance layers 87 of the bottom force 85, i.e., portions to becomeconductive parts, than the other portions, to the molding material layer95 in the thickness-wise direction of the molding material layer 95. Asa result, the conductive particles P dispersed in the molding materiallayer 95 are gathered at the portions where the magnetic field havingthe higher intensity is applied in the molding material layer 95, i.e.,the portions between the ferromagnetic substance layers 83 of the topforce 81 and their corresponding ferromagnetic substance layers 87 ofthe bottom force 85, and further oriented so as to align in thethickness-wise direction. In this state, the molding material layer 95is subjected to a curing treatment, whereby an anisotropicallyconductive elastomer sheet composed of a plurality of conductive parts,in which the conductive particles P are contained in a state oriented soas to align in the thickness-wise direction, and an insulating part formutually insulating these conductive parts, and having projected partsthat the conductive parts are protruding from the surface of theinsulating part is molded in a state that its peripheral edge has beensupported by the opening edge about the frame plate, thus producing ananisotropically conductive connector.

According to such an anisotropically conductive connector, it is hard tobe deformed and easy to handle because the anisotropically conductiveelastomer sheet is supported by the metal-made frame plate. Apositioning mark (for example, a hole) is formed in the frame plate inadvance, whereby the positioning and the holding and fixing to anintegrated circuit device can also be easily conducted upon anelectrically connecting operation to the integrated circuit device. Inaddition, a material low in coefficient of thermal expansion is used asa material for forming the frame plate, whereby the thermal expansion ofthe anisotropically conductive sheet is restrained by the frame plate,so that positional deviation between the conductive parts of the unevendistribution type anisotropically conductive elastomer sheet andelectrodes to be inspected of the integrated circuit device is preventedeven when they are subjected to thermal hysteresis by temperaturechange. As a result, a good electrically connected state can be stablyretained.

By the way, in a probe test conducted for integrated circuits formed ona wafer, a method that a probe test is collectively performed on a groupof integrated circuits composed of 16 or 32 integrated circuits among agreat number of integrated circuits formed on a wafer, and the probetest is successively performed on other groups of integrated circuitshas heretofore been adopted.

In recent years, there has been a demand for collectively performing aprobe test on, for example, 64 or 124 integrated circuits among a greatnumber of integrated circuits formed on a wafer, or all the integratedcircuits for the purpose of improving inspection efficiency and reducinginspection cost.

In a burn-in test on the other hand, it takes a long time toindividually conduct electrical inspection of a great number ofintegrated circuit devices because each integrated circuit device thatis an object of inspection is fine, and its handling is inconvenient,whereby inspection cost becomes considerably high. From such reasons,there has been proposed a WLBI (Wafer Lebel Burn-in) test in which theburn-in test is collectively performed on a great number of integratedcircuits formed on a wafer in the state of the wafer.

When a wafer that is an object of inspection is of large size of, forexample, at least 8 inches in diameter, and the number of electrodes tobe inspected formed thereon is, for example, at least 5,000,particularly at least 10,000, however, the following problems areinvolved when the above-described anisotropically conductive connectoris applied as a probe member for the probe test or WLBI test, since apitch between electrodes to be inspected in each integrated circuit isextremely small.

In other words, in order to inspect a wafer having a diameter of, forexample, 8 inches (about 20 cm), it is necessary to use ananisotropically conductive elastomer sheet having a diameter of about 8inches as an anisotropically conductive connector. However, such ananisotropically conductive elastomer sheet is large in the whole area,but each conductive part is fine, and the area proportion of thesurfaces of the conductive parts to the whole surface of theanisotropically conductive elastomer sheet is low. It is thereforeextremely difficult to surely produce such an anisotropically conductiveelastomer sheet.

In addition, since the conductive parts to be formed are fine andextremely small in pitch, it is difficult to surely produceanisotropically conductive elastomer sheet having necessary insulatingproperty between adjoining conductive parts. This is considered to beattributable to the following reasons.

As described above, the magnetic field having intensity distribution isapplied to the molding material layer with the conductive particlesexhibiting magnetism dispersed in the polymeric substance-formingmaterial in the thickness-wise direction thereof upon the production ofthe anisotropically conductive elastomer sheet, thereby formingportions, in which the conductive particles are densely gathered, andportions in which the conductive particles are sparse, and such amolding material layer is subjected to the curing treatment, therebyforming conductive parts, in which the conductive particles are denselycontained, and an insulating part, in which the conductive particles arenot contained at all or scarcely contained.

When an anisotropically conductive elastomer sheet adapting to a waferhaving a diameter of 8 inches or greater and at least 5,000 electrodesto be inspected is produced, however, the conductive particles are hardto be gathered to expected portions even when the above-described moldis used, and the magnetic field having the intensity distribution isapplied to the molding material layer, since magnetic fields byadjoining ferromagnetic substance layers influence each other. When ananisotropically conductive elastomer sheet having projected parts isproduced in particular, the movement of the conductive particles in alateral direction is inhibited by the recessed parts formed in themolding surfaces of the mold, so that the conductive particles areharder to be gathered at the expected portions.

Accordingly, in the resulting anisotropically conductive elastomersheet, the conductive particles are not filled in a necessary amount inthe conductive parts, whereby not only the conductivity of theconductive parts is deteriorated, but also the conductive particlesremain in the insulating part, so that an electric resistance valuebetween adjoining conductive parts is lowered to make it difficult tosecure necessary insulating property between the adjoining conductiveparts.

A wafer, on which integrated circuits having projected electrodes(bumps) have been formed, has been recently produced, and electricalinspection of the integrated circuits formed on this wafer is conductedin the production process thereof.

When the anisotropically conductive elastomer sheet having the projectedparts is used in the electrical inspection of such a wafer, however, theanisotropically conductive elastomer sheet involves a problem that itsdurability over repeated use is lowered.

More specifically, an operation that projected electrodes, which areelectrodes to be inspected in the wafer that is an object of inspection,are brought into contact under pressure with the conductive parts of theanisotropically conductive elastomer sheet is conducted repeatedly,whereby the projected parts of the conductive parts are crashed in theearly stage, and permanent deformation occurs in the conductive parts,so that stable electrical connection is not attained between theconductive parts and the electrodes to be inspected.

Methods for conducting a probe test as to integrated circuits formed ata high degree of integration on a wafer having a diameter of 8 inches or12 inches include a method that the wafer is divided into 2 or moreareas to collectively perform the probe test as to the integratedcircuits formed in each of the divided areas in addition to a method ofcollectively conducting the probe test as to all the integrated circuitsformed on the wafer. An anisotropically conductive connector used insuch a method is desired to have high durability over repeated use forthe purpose of reducing inspection cost.

Prior Art. 1: Japanese Patent Application Laid-Open No. 93393/1976;

Prior Art. 2: Japanese Patent Application Laid-Open No. 147772/1978;

Prior Art. 3: Japanese Patent Application Laid-Open No. 250906/1986;

Prior Art. 4: Japanese Patent Application Laid-Open No. 40224/1999.

DISCLOSURE OF THE INVENTION

The present invention has been made on the basis of the foregoingcircumstances and has as its first object the provision of ananisotropically conductive connector, by which positioning, and holdingand fixing to a wafer that is an object of inspection can be conductedwith ease even when the wafer has a large area of, for example, 8 inchesor greater in diameter, and the pitch of electrodes to be inspected inintegrated circuits formed is small, good conductivity is surelyachieved as to all conductive parts for connection, insulating propertybetween adjoining conductive parts for connection is surely attained,and moreover the good conductivity is retained over a long period oftime even when it is used repeatedly.

A second object of the present invention is to provide ananisotropically conductive connector that good conductivity is achievedas to conductive parts for connection even when it is pressurized undera small load, in addition to the above object.

A third object of the present invention is to provide an anisotropicallyconductive connector that a good electrically connected state is stablyretained even by environmental changes such as thermal hysteresis bytemperature change, in addition to the above objects.

A fourth object of the present invention is to provide a probe member,by which positioning, and holding and fixing to a wafer that is anobject of inspection can be conducted with ease even when the wafer hasa large area of, for example, 8 inches or greater in diameter, and thepitch of electrodes to be inspected in integrated circuits formed issmall, and moreover reliability on connection to each electrode to beinspected is high, and good conductivity is retained over a long periodof time even when it is used repeatedly.

A fifth object of the present invention is to provide an anisotropicallyconductive connector and a probe member, which have high durability inrepeated use even when a probe test is performed as to integratedcircuits formed at a high degree of integration on a wafer having adiameter of 8 inches or 12 inches.

A sixth object of the present invention is to provide an anisotropicallyconductive connector and a probe member, which have high durability inrepeated use when electrical inspection is performed as to integratedcircuits having projected electrodes formed at a high degree ofintegration on a large-area wafer.

A seventh object of the present invention is to provide a waferinspection apparatus and a wafer inspection method for conductingelectrical inspection of a plurality of integrated circuits formed on awafer in a state of the wafer using the above-described probe member.

According to the present invention, there is provided an anisotropicallyconductive connector comprising elastic anisotropically conductive filmseach having a functional part, in which a plurality of conductive partsfor connection containing conductive particles and extending in athickness-wise direction of the film have been arranged in a statemutually insulated by an insulating part,

wherein assuming that a thickness of the conductive parts for connectionin the functional part of the elastic anisotropically conductive film isT1 and a thickness of the insulating part in the functional part is T2,a ratio (T2/T1) is at least 0.9.

According to the present invention, there is also provided ananisotropically conductive connector suitable for use in conductingelectrical inspection of each of a plurality of integrated circuitsformed on a wafer in a state of the wafer, which comprises:

a frame plate, in which a plurality of anisotropically conductivefilm-arranging holes each extending through in a thickness-wisedirection of the frame plate have been formed corresponding to electroderegions, in which electrodes to be inspected have been arranged, in allor part of the integrated circuits formed on the wafer, which is anobject of inspection, and a plurality of elastic anisotropicallyconductive films arranged in the respective anisotropically conductivefilm-arranging holes in this frame plate and each supported by theperipheral part about the anisotropically conductive film-arranginghole,

wherein each of the elastic anisotropically conductive films is equippedwith a functional part having a plurality of conductive parts forconnection arranged corresponding to the electrodes to be inspected inthe integrated circuits formed on the wafer, which is the object ofinspection, containing conductive particles exhibiting magnetism at ahigh density and extending in a thickness-wise direction of the film,and an insulating part mutually insulating these conductive parts forconnection, and

wherein assuming that a thickness of the conductive parts for connectionin the functional part of the elastic anisotropically conductive film isT1 and a thickness of the insulating part in the functional part is T2,a ratio (T2/T1) is at least 0.9.

In such an anisotropically conductive connector, at least one surface ofthe functional part in each of the elastic anisotropically conductivefilms may preferably be flat.

It may be preferable that said at least one flat surface of thefunctional part in each of the elastic anisotropically conductive filmsbe formed so as to project from any other portion, and

assuming that a sum total of areas of one surfaces of the functionalparts of all the elastic anisotropically conductive films is S1, and anarea of a surface of the wafer, which is the object of inspection, on aside that the electrodes to be inspected have been formed, is S2, aratio S1/S2 be 0.001 to 0.3.

The coefficient of linear thermal expansion of the frame plate maypreferably be at most 3×10⁻⁵/K.

According to the present invention, there is further provided a probemember suitable for use in conducting electrical inspection of each of aplurality of integrated circuits formed on a wafer in a state of thewafer, which comprises:

a circuit board for inspection, on the surface of which inspectionelectrodes have been formed in accordance with a pattern correspondingto a pattern of electrodes to be inspected of the integrated circuitsformed on the wafer, which is an object of inspection, and theabove-described anisotropically conductive connector having the frameplate and arranged on the surface of the circuit board for inspection.

In the probe member according to the present invention, it may bepreferable that the coefficient of linear thermal expansion of the frameplate in the anisotropically conductive connector be at most 3×10⁻⁵/K,and the coefficient of linear thermal expansion of a base materialmaking up the circuit board for inspection be at most 3×10⁻⁵/K.

In the probe member, a sheet-like connector composed of an insulatingsheet and a plurality of electrode structures each extending through theinsulating sheet in a thickness-wise direction thereof and arranged inaccordance with a pattern corresponding to the pattern of the electrodesto be inspected may be arranged on the anisotropically conductiveconnector.

According to the present invention, there is still further provided awafer inspection apparatus for conducting electrical inspection of eachof a plurality of integrated circuits formed on a wafer in a state ofthe wafer, which comprises:

the probe member described above, wherein electrical connection to theintegrated circuits formed on the wafer, which is an object ofinspection, is achieved through the probe member.

According to the present invention, there is yet still further provideda wafer inspection method comprising a step of electrically connectingeach of a plurality of integrated circuits formed on a wafer to a testerthrough the probe member described above to perform electricalinspection of the integrated circuits formed on the wafer.

EFFECTS OF THE INVENTION

According to the anisotropically conductive connectors of the presentinvention, a part to be supported is formed at the peripheral edge ofthe functional part having the conductive parts for connection in eachof the elastic anisotropically conductive films, and this part to besupported is fixed to the periphery about the anisotropically conductivefilm-arranging hole in the frame plate, so that the anisotropicallyconductive connectors are hard to be deformed and easy to handle, andthe positioning and the holding and fixing to a wafer, which is anobject of inspection, can be easily conducted in an electricallyconnecting operation to the wafer.

In addition, there is no or little difference in thickness between theconductive parts for connection and the insulating part in thefunctional part of each of the elastic anisotropically conductive films,so that the mold used in the formation of the elastic anisotropicallyconductive films has a flat molding surface or a molding surface smallin the depth of the recessed parts, and so the movement of theconductive particles is not inhibited when the magnetic field is appliedto the molding material layers, and the conductive particles can beeasily gathered to portions to become the conductive parts forconnection almost without remaining at a portion to become theinsulating part in the molding material layer. As a result, goodconductivity is surely achieved as to all the conductive parts forconnection formed and sufficient insulating property is surely attainedbetween adjoining conductive parts for connection.

Further, there is no or little difference in height level between theconductive parts for connection and the insulating part in the surfaceof the functional part of each of the anisotropically conductive films,so that the occurrence of permanent deformation of the conductive partsfor connection due to crush of the projected parts thereof is avoided orinhibited even when a wafer, which is an object of inspection, hasprojected electrodes to be inspected, and so high durability overrepeated use is attained.

According to the construction that one flat surface of the functionalpart is formed so as to project from any other portion, and the ratio ofthe area of one surfaces of the functional parts to the area of surfaceof the wafer, which is the object of inspection, falls within aspecified range, a load is applied concentratedly only to the functionalparts when the anisotropically conductive connector is pressurized in athickness-wise direction, so that good conductivity is surely achievedon the conductive parts for connection even when the anisotropicallyconductive connector is pressurized under a small load.

Since the respective anisotropically conductive film-arranging holes inthe frame plate are formed corresponding to the electrode regions, inwhich electrodes to be inspected have been formed, of integratedcircuits in a wafer, which is an object of inspection, and the elasticanisotropically conductive film arranged in each of the anisotropicallyconductive film-arranging holes may be small in area, the individualelastic anisotropically conductive films are easy to be formed. Inaddition, since the elastic anisotropically conductive film small inarea is little in the absolute quantity of thermal expansion in a planedirection of the elastic anisotropically conductive film even when it issubjected to thermal hysteresis, the thermal expansion of the elasticanisotropically conductive film in the plane direction is surelyrestrained by the frame plate by using a material having a lowcoefficient of linear thermal expansion as that for forming the frameplate. Accordingly, a good electrically connected state can be stablyretained even when the WLBI test is performed on a large-area wafer.

According to the probe members of the present invention, positioning,and holding and fixing to a wafer, which is an object of inspection, canbe conducted with ease in an electrically connecting operation to thewafer, and moreover the necessary conductivity can be retained over along period of time even when they are used repeatedly in inspection ofwafers, on which integrated circuits having projected electrodes havebeen formed.

According to the wafer inspection apparatus and wafer inspection methodof the present invention, electrical connection to electrodes to beinspected of a wafer, which is an object of inspection, is achievedthrough the above probe member, so that positioning, and holding andfixing to the wafer can be conducted with ease even when the pitch ofthe electrodes to be inspected is small. In addition, the necessaryelectrical inspection can be stably performed over a long period of timeeven when the inspection is conducted repeatedly on wafers, on whichintegrated circuits having projected electrodes have been formed.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a plan view illustrating an exemplary anisotropicallyconductive connector according to the present invention.

FIG. 2 is a plan view illustrating, on an enlarged scale, a part of theanisotropically conductive connector shown in FIG. 1.

FIG. 3 is a plan view illustrating, on an enlarged scale, an elasticanisotropically conductive film in the anisotropically conductiveconnector shown in FIG. 1.

FIG. 4 is a cross-sectional view illustrating, on an enlarged scale, theelastic anisotropically conductive film in the anisotropicallyconductive connector shown in FIG. 1.

FIG. 5 is a cross-sectional view illustrating a state that a moldingmaterial has been applied to a mold for molding elastic anisotropicallyconductive films to form molding material layers.

FIG. 6 is a cross-sectional view illustrating, on an enlarged scale, apart of the mold for molding elastic anisotropically conductive film.

FIG. 7 is a cross-sectional view illustrating a state that a frame platehas been arranged through spacers between a top force and a bottom forcein the mold shown in FIG. 5.

FIG. 8 is a cross-sectional view illustrating a state that moldingmaterial layers of the intended form have been formed between the topforce and the bottom force in the mold.

FIG. 9 is a cross-sectional view illustrating, on an enlarged scale, themolding material layer shown in FIG. 8.

FIG. 10 is a cross-sectional view illustrating a state that a magneticfield having an intensity distribution has been applied to the moldingmaterial layer shown in FIG. 9 in a thickness-wise direction thereof.

FIG. 11 is a cross-sectional view illustrating the construction of anexemplary wafer inspection apparatus according to the present invention.

FIG. 12 is a cross-sectional view illustrating the construction of aprincipal part of a probe member in the wafer inspection apparatus shownin FIG. 11.

FIG. 13 is a cross-sectional view illustrating the construction of awafer inspection apparatus according to another embodiment of thepresent invention.

FIG. 14 is a cross-sectional view illustrating the construction of aprincipal part of a probe member in the wafer inspection apparatus shownin FIG. 13.

FIG. 15 is a plan view illustrating, on an enlarged scale, an elasticanisotropically conductive film in an anisotropically conductiveconnector according to another embodiment of the present invention.

FIG. 16 is a cross-sectional view illustrating, on an enlarged scale,the elastic anisotropically conductive film in the anisotropicallyconductive connector according to said another embodiment of the presentinvention.

FIG. 17 is a plan view illustrating, on an enlarged scale, an elasticanisotropically conductive film in an anisotropically conductiveconnector according to a further embodiment of the present invention.

FIG. 18 is a cross-sectional view illustrating the construction of awafer inspection apparatus according to a further embodiment of thepresent invention.

FIG. 19 is a cross-sectional view illustrating the construction of aprincipal part of a probe member in the wafer inspection apparatus shownin FIG. 18.

FIG. 20 is a cross-sectional view illustrating the construction of awafer inspection apparatus for inspecting wafers having projectedelectrodes.

FIG. 21 is a cross-sectional view illustrating the construction of aprincipal part of a probe member in the wafer inspection apparatus shownin FIG. 20.

FIG. 22 is a plan view illustrating, on an enlarged scale, an elasticanisotropically conductive film in an anisotropically conductiveconnector according to a still further embodiment of the presentinvention.

FIG. 23 is a top view of a wafer for evaluation used in Examples.

FIG. 24 illustrates a position of a region of electrodes to be inspectedin an integrated circuit formed on the wafer for evaluation shown inFIG. 23.

FIG. 25 illustrates the electrodes to be inspected in the integratedcircuit formed on the wafer for evaluation shown in FIG. 23.

FIG. 26 is a top view of a frame plate produced in Example.

FIG. 27 illustrates, on an enlarged scale, a part of the frame plateshown in FIG. 26.

FIG. 28 illustrates, on an enlarged scale, a molding surface of a moldproduced in Example.

FIG. 29 is a cross-sectional view illustrating, on an enlarged scale, apart of a mold for molding elastic anisotropically conductive film usedin obtaining a comparative anisotropically conductive connector.

FIG. 30 illustrates, on an enlarged scale, a molding surface of the moldfor molding elastic anisotropically conductive film used in obtainingthe comparative anisotropically conductive connector.

FIG. 31 is a cross-sectional view illustrating a state that a frameplate has been arranged within a mold in a process for producing aconventional anisotropically conductive connector, and a moldingmaterial layer has been formed.

DESCRIPTION OF CHARACTERS

-   1 Probe member,-   2 Anisotropically conductive connector,-   3 Pressurizing plate,-   4 Wafer mounting table,-   5 Heater,-   6 Wafer,-   7 Electrodes to be inspected,-   10 Frame plate,-   11 Anisotropically conductive film-arranging holes,-   15 Air circulating holes,-   16 Positioning holes,-   20 Elastic anisotropically conductive films,-   20A Molding material layers,-   21 Functional parts,-   22 Conductive parts for connection,-   23 Insulating part,-   24 Projected parts,-   25 Parts to be supported,-   26 Conductive parts for non-connection,-   30 Circuit board for inspection,-   31 Inspection electrodes,-   40 Sheet-like connector,-   41 Insulating sheet,-   42 Electrode structures,-   43 Front-surface electrode parts,-   44 Back-surface electrode parts,-   45 Short circuit parts,-   50 Chamber,-   51 Evacuation pipe,-   55 O-rings,-   60 Mold,-   61 Top force,-   62 Base plate,-   63, 63 a Ferromagnetic substance layers,-   64 Non-magnetic substance layers,-   64 a, 64 b, 64 c Recessed parts,-   65 Bottom force,-   66 Base plate,-   67, 67 a Ferromagnetic substance layers,-   68 Non-magnetic substance layers,-   68 a, 68 b, 68 c Recessed parts,-   69 a, 69 b Spacers,-   81 Top force,-   82 Base plate,-   83 Ferromagnetic substance layers,-   84 Non-magnetic substance layers,-   84 a Recessed parts-   85 Bottom force,-   86 Base plate-   87 Ferromagnetic substance layers,-   88 Non-magnetic substance layers, 88 a Recessed parts,-   90 Frame plate,-   91 Opening,-   95 Molding material layer P Conductive particles.

BEST MODE FOR CARRYING OUT THE INVENTION

The embodiments of the present invention will hereinafter be describedin details.

[Anisotropically Conductive Connector]

FIG. 1 is a plan view illustrating an exemplary anisotropicallyconductive connector according to the present invention, FIG. 2 is aplan view illustrating, on an enlarged scale, a part of theanisotropically conductive connector shown in FIG. 1, FIG. 3 is a planview illustrating, on an enlarged scale, an elastic anisotropicallyconductive film in the anisotropically conductive connector shown inFIG. 1, and FIG. 4 is a cross-sectional view illustrating, on anenlarged scale, the elastic anisotropically conductive film in theanisotropically conductive connector shown in FIG. 1.

The anisotropically conductive connector shown in FIG. 1 is that usedfor conducting electrical inspection of each of, for example, aplurality of integrated circuits formed on a wafer in a state of thewafer and has a frame plate 10 in which a plurality of anisotropicallyconductive film-arranging holes 11 (indicated by broken lines) eachextending through in a thickness-wise direction of the frame plate havebeen formed as illustrated in FIG. 2. The anisotropically conductivefilm-arranging holes 11 in this frame plate 10 are formed in accordancewith a pattern of electrode regions, in which electrodes to be inspectedhave been formed in the integrated circuits formed on the wafer that isan object of inspection. Elastic anisotropically conductive films 20having conductivity in the thickness-wise direction are arranged in therespective anisotropically conductive film-arranging holes 11 in theframe plate 10 in a state supported by the peripheral part about theanisotropically conductive film-arranging hole 11 of the frame plate 10and in a state independent of adjacent elastic anisotropicallyconductive films 20 to each other. In the frame plate 10 of thisembodiment, are formed air circulating holes 15 for passing air betweenthe anisotropically conductive connector and a member adjacent theretowhen a pressurizing means of a pressure reducing system is used in awafer inspection apparatus, which will be described subsequently. Inaddition, positioning holes 16 for positioning between the wafer, whichis the object of inspection, and a circuit board for inspection areformed.

Each of the elastic anisotropically conductive films 20 is formed by anelastic polymeric substance and, as illustrated in FIG. 3, has afunctional part 21 composed of a plurality of conductive parts 22 forconnection each extending in the thickness-wise direction (directionperpendicular to the paper in FIG. 3) of the film and an insulating part23 formed around the respective conductive parts 22 for connection andmutually insulating these conductive parts 22 for connection. Thefunctional part 21 is arranged so as to be located within theanisotropically conductive film-arranging hole 11 in the frame plate 10.The conductive parts 22 for connection in the functional part 21 arearranged in accordance with a pattern corresponding to a pattern of theelectrodes to be inspected in the integrated circuit formed on thewafer, which is the object of inspection, and electrically connected tothe electrodes to be inspected in the inspection of the wafer.

At a peripheral edge of the functional part 21, a part 25 to besupported, which is fixed to and supported by the periphery about theanisotropically conductive film-arranging hole 11 in the frame plate 10,is formed integrally and continuously with the functional part 21. Morespecifically, the part 25 to be supported in this embodiment is shapedin a forked form and fixed and supported in a closely contacted state soas to grasp the periphery about the anisotropically conductivefilm-arranging hole 11 in the frame plate 10.

In the conductive parts 22 for connection in the functional part 21 ofthe elastic anisotropically conductive film 20, conductive particles Pexhibiting magnetism are contained at a high density in a state orientedso as to align in the thickness-wise direction as illustrated in FIG. 4.On the other hand, the insulating part 23 does not contain theconductive particles P at all or scarcely contain them. In thisembodiment, the part 25 to be supported in the elastic anisotropicallyconductive film 20 contains the conductive particles P.

In the anisotropically conductive connector according to the presentinvention, assuming that a thickness of the conductive parts 22 forconnection in the functional part 21 of the elastic anisotropicallyconductive film 20 is T1 and a thickness of the insulating part 23 inthe functional part 21 is T2, a ratio (T2/T1) of the thickness of theinsulating part 23 to the thickness of the conductive parts 22 forconnection is at least 0.9, preferably 0.92 to 1.2. In this embodiment,both surfaces of the functional part 21 of the elastic anisotropicallyconductive film 20 are formed in a flat surface, and so the ratio(T2/T1) of the thickness of the insulating part 23 to the thickness ofthe conductive parts 22 for connection is 1. It is particularlypreferred that the ratio (T2/T1) be 1 as described above, since yield inthe production of the anisotropically conductive connector is improved,rise in the electric resistance of the conductive parts for connectiondue to deformation of the conductive parts for connection is inhibitedeven when the electrodes to be inspected have a projected form, anddurability in repeated use is more improved.

If this ratio (T2/T1) is too low, conductive particles in a moldingmaterial layer are hard to be gathered to portions to become theconductive parts 22 for connection when a magnetic field having anintensity distribution is applied to the molding material layer in theformation of the anisotropically conductive film 20, so that an electricresistance of the resulting conductive parts 22 for connection becomeshigh, or an electric resistance between adjoining conductive parts 22for connection becomes low in some cases.

In the anisotropically conductive connector in this embodiment, thefunctional part 21 in each of the elastic anisotropically conductivefilms 20 has a thickness greater than the thickness of the part 25 to besupported and is formed in such a manner that both surfaces of eachfunctional part 21 protrudes from the part 25 to be supported.

In such an anisotropically conductive connector, assuming that a sumtotal of areas of one surfaces of the functional parts of all theelastic anisotropically conductive films is S1, and an area of a surfaceof the wafer, which is the object of inspection, on a side that theelectrodes to be inspected have been formed, is S2, a ratio S1/S2 ispreferably 0.001 to 0.3, more preferably 0.002 to 0.2.

If the value of this ratio S1/S2 is too low, there is a possibility thatwhen such an anisotropically conductive connector is released from apressurized state, each of the elastic anisotropically conductive films20 may remain in a state compressed and become hard to restore to theoriginal form either by the tackiness of the functional part 21 of eachof the elastic anisotropically conductive films 20 by the weight of thecircuit board for inspection or by tackiness of the elasticanisotropically conductive film 20 itself, whereby the durability inrepeated use of the elastic anisotropically conductive films 20 may bemarkedly lowered in some cases. If the value of this ratio S1/S2 is toohigh on the other hand, such an anisotropically conductive connectormust be pressurized under a considerably heavy load for achievingelectrical connection to a wafer that is an object of inspection.Therefore, it is necessary to install a large-sized pressurizingmechanism in a wafer inspection apparatus. As a result, a problem thatthe wafer inspection apparatus itself becomes large-sized, and theproduction cost of the wafer inspection apparatus is increased arises.Since the anisotropically conductive connector is pressurized under aconsiderably heavy load, a problem that the anisotropically conductiveconnector, the circuit board for inspection and the wafer, which is theobject of inspection, tend to be damaged also arises.

The thickness of the frame plate 10 varies according to the materialthereof, but is preferably 20 to 600 μm, more preferably 40 to 400 μm.

If this thickness is less than 20 μm, the strength required upon use ofthe resulting anisotropically conductive connector is not achieved, andthe durability thereof is liable to be lowered. In addition, suchstiffness as the form of the frame plate is retained is not achieved,and the handling property of the anisotropically conductive connectorbecomes low. If the thickness exceeds 600 μm on the other hand, theelastic anisotropically conductive films 20 formed in theanisotropically conductive film-arranging holes 11 become too great inthickness, and it may be difficult in some cases to achieve goodconductivity in the conductive parts 22 for connection and insulatingproperty between adjoining conductive parts 22 for connection.

The form and size in a plane direction of the anisotropically conductivefilm-arranging holes 11 in the frame plate 10 are designed according tothe size, pitch and pattern of electrodes to be inspected in a waferthat is an object of inspection.

No particular limitation is imposed on a material for forming the frameplate 10 so far as it has such stiffness as the resulting frame plate 10is hard to be deformed, and the form thereof is stably retained. Forexample, various kinds of materials such as metallic materials, ceramicmaterials and resin materials may be used. When the frame plate 10 isformed by, for example, a metallic material, an insulating film may beformed on the surface of the frame plate 10.

Specific examples of the metallic material for forming the frame plate10 include metals such as iron, copper, nickel, chromium, cobalt,magnesium, manganese, molybdenum, indium, lead, palladium, titanium,tungsten, aluminum, gold, platinum and silver, and alloys or alloysteels composed of a combination of at least two of these metals.

Specific examples of the resin material forming the frame plate 10include liquid crystal polymers and polyimide resins.

The frame plate 10 may preferably exhibit magnetism at least at theperipheral portion about each of the anisotropically conductivefilm-arranging holes 11, i.e., a portion supporting the elasticanisotropically conductive film 20 in that the conductive particles Pcan be caused to be contained with ease in the part 25 to be supportedin the elastic anisotropically conductive film 20 by a process whichwill be described subsequently. Specifically, this portion maypreferably have a saturation magnetization of at least 0.1 Wb/m². Inparticular, the whole frame plate 10 may preferably be formed by amagnetic substance in that the frame plate 10 is easy to be produced.

Specific examples of the magnetic substance forming such a frame plate10 include iron, nickel, cobalt, alloys of these magnetic metals, andalloys or alloy steels of these magnetic metals with any other metal.

When the resulting anisotropically conductive connector is used in theWLBI test, it is preferable to use a material having a coefficient oflinear thermal expansion of at most 3×10⁻⁵/K, more preferably −1×10⁻⁷ to1×10⁻⁵/K, particularly preferably 1×10⁻⁶ to 8×10⁻⁶/K as a material forforming the frame plate 10.

Specific examples of such a material include invar alloys such as invar,Elinvar alloys such as Elinvar, and alloys or alloy steels of magneticmetals, such as superinvar, covar and 42 alloy.

The overall thickness of the functional part 21 of the elasticanisotropically conductive film 20 is preferably 40 to 3,000 μm, morepreferably 50 to 2,500 μm, particularly preferably 70 to 2,000 μm. Whenthis thickness is 40 μm or greater, elastic anisotropically conductivefilms 20 having sufficient strength are provided with certainty. Whenthis thickness is 3,000 μm or smaller on the other hand, conductiveparts 22 for connection having necessary conductive properties areprovided with certainty.

The thickness (thickness of one of the forked portions in theillustrated embodiment) of the part 25 to be supported is preferably 5to 600 μm, more preferably 10 to 500 μm.

It is not essential for the part 25 to be supported to be form in theforked form so as to be fixed to both surfaces of the frame plate 10,and it may be fixed to only one surface of the frame plate 10.

As the elastic polymeric substance forming the elastic anisotropicallyconductive films 20, a heat-resistant polymeric substance having acrosslinked structure is preferred. Various materials may be used ascurable polymeric substance-forming materials usable for obtaining sucha crosslinked polymeric substance. However, liquid silicone rubber ispreferred.

The liquid silicone rubber may be any of addition type and condensationtype. However, the addition type liquid silicone rubber is preferred.This addition type liquid silicone rubber is that curable by a reactionof a vinyl group with a Si—H bond and includes a one-pack type(one-component type) composed of polysiloxane having both vinyl groupand Si—H bond and a two-pack type (two-components type) composed ofpolysiloxane having a vinyl group and polysiloxane having an Si—H bond.In the present invention, addition type liquid silicone rubber of thetwo-pack type is preferably used.

As the addition type liquid silicone rubber, is used that having aviscosity of preferably 100 to 1,250 Pa·s, more preferably 150 to 800Pa·s, particularly preferably 250 to 500 Pa·s at 23° C. If thisviscosity is lower than 100 Pa·s, precipitation of the conductiveparticles in such addition type liquid silicone rubber is easy to occurin a molding material for obtaining the elastic anisotropicallyconductive films 20, which will be described subsequently, so that goodstorage stability is not obtained. In addition, the conductive particlesare not oriented so as to align in the thickness-wise direction when aparallel magnetic field is applied to the molding material layer, sothat it may be difficult in some cases to form chains of the conductiveparticles in an even state. If this viscosity exceeds 1,250 Pa·s on theother hand, the viscosity of the resulting molding material becomes toohigh, so that it may be difficult in some cases to form the moldingmaterial layer in the mold. In addition, the conductive particles arenot sufficiently moved even when a parallel magnetic field is applied tothe molding material layer. Therefore, it may be difficult in some casesto orient the conductive particles so as to align in the thickness-wisedirection.

The viscosity of such addition type liquid silicone rubber can bemeasured by means of a Brookfield type viscometer.

When the elastic anisotropically conductive films 20 are formed by acured product (hereinafter referred to as “cured silicon rubber”) of theliquid silicone rubber, the cured silicone rubber preferably has acompression set of at most 10%, more preferably at most 8%, still morepreferably at most 6% at 150° C. If the compression set exceeds 10%,chains of the conductive particles P in the conductive part 22 forconnection are disordered when the resulting anisotropically conductiveconnector is used repeatedly under a high-temperature environment. As aresult, it is difficult to retain the necessary conductivity.

In the present invention, the compression set of the cured siliconerubber can be measured by a method in accordance with JIS K 6249.

The cured silicone rubber forming the elastic anisotropically conductivefilms 20 preferably has a durometer A hardness of 10 to 60, morepreferably 15 to 60, particularly preferably 20 to 60 at 23° C. If thedurometer A hardness is lower than 10, the insulating part 23 mutuallyinsulating the conductive parts 22 for connection is easilyover-distorted when pressurized, and so it may be difficult in somecases to retain the necessary insulating property between the conductiveparts 22 for connection. If the durometer A hardness exceeds 60 on theother hand, pressurizing force by a considerably heavy load is requiredfor giving proper distortion to the conductive parts 22 for connection,so that, for example, a wafer, which is an object of inspection, tendsto cause great deformation or breakage.

In the present invention, the durometer A hardness of the cured siliconerubber can be measured by a method in accordance with JIS K 6249.

Further, the cured silicone rubber for forming the elasticanisotropically conductive films 20 preferably has tear strength of atleast 8 kN/m, more preferably at least 10 kN/m, still more preferably atleast 15 kN/m, particularly preferably at least 20 kN/m at 23° C. If thetear strength is less than 8 kN/m, the resulting elastic anisotropicallyconductive films 20 tend to deteriorate durability when they aredistorted in excess.

In the present invention, the tear strength of the cured silicone rubbercan be measured by a method in accordance with JIS K 6249.

As the addition type liquid silicone rubber having such properties, maybe used that marketed as liquid silicone rubber “KE2000” series,“KE1950” series or “KE1990” series from Shin-Etsu Chemical Co., Ltd.

In the present invention, a proper curing catalyst may be used forcuring the addition type liquid silicone rubber. As such a curingcatalyst, may be used a platinum-containing catalyst. Specific examplesthereof include publicly known catalysts such as platinic chloride andsalts thereof, platinum-unsaturated group-containing siloxane complexes,vinylsiloxane-platinum complexes,platinum-1,3-divinyltetramethyldisiloxane complexes, complexes oftriorganophosphine or phosphite with platinum, acetyl acetate-platinumchelates, and cyclic diene-platinum complexes.

The amount of the curing catalyst used is suitably selected in view ofthe kind of the curing catalyst and other curing treatment conditions.However, it is generally 3 to 15 parts by weight per 100 parts by weightof the addition type liquid silicone rubber.

In order to improve the thixotropic property of the addition type liquidsilicone rubber, adjust the viscosity, improve the dispersion stabilityof the conductive particles, provide a base material having highstrength or the like, a general inorganic filler such as silica powder,colloidal silica, aerogel silica or alumina may be contained in theaddition type liquid silicone rubber as needed.

No particular limitation is imposed on the amount of such an inorganicfiller used. However, the use in a too large amount is not preferredbecause the orientation of the conductive particles by a magnetic fieldcannot be sufficiently achieved.

The number average particle diameter of the conductive particles P ispreferably 3 to 30 μm, more preferably 6 to 15 μm.

Assuming that the number average particle diameter of the conductiveparticles P is Dn, and the weight average particle diameter thereof isDw, conductive particles, whose ratio Dw/Dn (hereinafter referred to as“ratio Dw/Dn” merely) of the weight average particle diameter to thenumber average particle diameter is at most 5, are preferably used asthe conductive particles P. Those having a ratio Dw/Dn of at most 3 aremore preferably used. Necessary insulating property between adjoiningconductive parts 22 for connection can be attained with more certaintyby using such conductive particles.

In the present invention, the average particle diameter of the particlesmeans a value measured by a laser diffraction scattering method.

Further, the conductive particles P preferably have a coefficient ofvariation of particle diameter of at most 50%, more preferably at most35.

In the present invention, the coefficient of variation of particlediameter is a value determined in accordance with an expression:(σ/Dn)×100, wherein σ is a standard deviation value of the particlediameter.

If the coefficient of variation of particle diameter of the conductiveparticles P exceeds 50%, it is difficult to attain the necessaryinsulating property between adjoining conductive parts 22 for connectionwith certainty.

No particular limitation is imposed on the shape of the conductiveparticles P. However, they are preferably in the shape of a sphere orstar, or secondary particles obtained by aggregating these particlesfrom the viewpoint of permitting easy dispersion of these particles inthe polymeric substance-forming material.

Particles obtained by coating the surfaces of core particles(hereinafter also referred to as “magnetic core particles”) exhibitingmagnetism with a high-conductive metal are preferably used as theconductive particles P.

The term “high-conductive metal” as used herein means a metal having anelectric conductivity of at least 5×10⁶ Ω⁻¹m⁻¹ at 0° C.

As a material for forming the magnetic core particles, may be used iron,nickel, cobalt, a material obtained by coating such a metal to copper ora resin, or the like. Those having a saturation magnetization of atleast 0.1 Wb/m² may be preferably used. The saturation magnetizationthereof is more preferably at least 0.3 Wb/m², particularly preferably0.5 Wb/m². Specific examples of the material include iron, nickel,cobalt or alloys thereof. Among these, nickel is preferred.

When this saturation magnetization is at least 0.1 Wb/m², the conductiveparticles P can be easily moved in the molding material layers forforming the elastic anisotropically conductive films 20 by a process,which will be described subsequently, whereby the conductive particles Pcan be surely moved to portions to become conductive parts forconnection in the molding material layer to form chains of theconductive particles P.

As the high-conductive metal for coating the magnetic core particles,may be used gold, silver, rhodium, platinum, chromium or the like. Amongthese, gold is preferably used in that it is chemically stable and has ahigh electric conductivity.

In order to obtain conductive parts 22 for connection having highconductivity, particles, in which a proportion [(mass of high-conductivemetal/mass of core particles)×100] of the high-conductive metal to thecore particles is at least 15% by mass, are preferably used, and theproportion of the high-conductive metal to the core particles is morepreferably 25 to 35% by mass.

The water content in the conductive particles P is preferably at most5%, more preferably at most 3%, still more preferably at most 2%,particularly preferably at most 1%. The use of the conductive particlesP satisfying such conditions can prevent or inhibit the occurrence ofbubbles in the molding material layer upon a curing treatment of themolding material layer in the production process, which will bedescribed subsequently.

Such conductive particles P may be obtained in accordance with, forexample, the following process.

Particles are first formed from a ferromagnetic substance in accordancewith a method known per se in the art, or commercially availableparticles of a ferromagnetic substance are provided. The particles aresubjected to a classification treatment as needed.

The classification treatment of the particles can be conducted by meansof, for example, a classifier such as an air classifier or sonicclassifier.

Specific conditions for the classification treatment are suitably presetaccording to the intended number average particle diameter of themagnetic core particles, the kind of the classifier, and the like.

Surfaces of the magnetic core particles are then treated with an acidand further washed with, for example, purified water, thereby removingimpurities such as dirt, foreign matter and oxidized films present onthe surfaces of the magnetic core particles. Thereafter, the surfaces ofthe magnetic core particles are coated with a high-conductive metal,thereby obtaining conductive particles exhibiting magnetism.

As examples of the acid used for treating the surfaces of the magneticcore particles, may be mentioned hydrochloric acid.

As a method for coating the surfaces of the magnetic core particles withthe high-conductive metal, may be used electroless plating, displacementplating or the like. However, the method is not limited to thesemethods.

A process for producing the conductive particles by the electrolessplating or displacement plating will be described. The magnetic coreparticles subjected to the acid treatment and washing treatment arefirst added to a plating solution to prepare a slurry, and electrolessplating or displacement plating on the magnetic core particles isconducted while stirring the slurry. The particles in the slurry arethen separated from the plating solution. Thereafter, the particlesseparated are subjected to a washing treatment with, for example,purified water, thereby obtaining conductive particles with the surfacesof the magnetic core particles coated with the high-conductive metal.

Alternatively, primer plating may be conducted on the surfaces of themagnetic core particles to form a primer plating layer, and a platinglayer composed of the high-conductive metal may be then formed on thesurface of the primer plating layer. No particular limitation is imposedon the process for forming the primer plating layer and the platinglayer formed thereon. However, it is preferable to form the primerplating layer on the surfaces of the magnetic core particles by theelectroless plating and then form the plating layer composed of thehigh-conductive metal on the surface of the primer plating layer by thedisplacement plating.

No particular limitation is imposed on the plating solution used in theelectroless plating or displacement plating, and various kinds ofcommercially available plating solutions may be used.

The conductive particles obtained in such a manner are subjected to aclassification treatment for the purpose of providing particles havingthe above-described particle diameter and particle diameterdistribution.

As a classifier for conducting the classification treatment of theconductive particles, may be used that exemplified as the classifierused in the above-described classification treatment of the magneticcore particles. However, at least the air classifier is preferably used.The conductive particles are subjected to a classification treatment bythe air classifier, whereby conductive particles having theabove-described particle diameter and particle diameter distribution canbe surely obtained.

The conductive particles P may be treated with a coupling agent such asa silane coupling agent as needed. By treating the surfaces of theconductive particles P with the coupling agent, the adhesion property ofthe conductive particles P to the elastic polymeric substance isimproved. As a result, durability in repeated use of the resultingelastic anisotropically conductive films 20 become high.

The amount of the coupling agent used is suitably selected within limitsnot affecting the conductivity of the conductive particles P. However,it is preferably such an amount that a coating rate (proportion of anarea coated with the coupling agent to the surface area of theconductive particles) of the coupling agent on the surfaces of theconductive particles P amounts to at least 5%, more preferably 7 to100%, further preferably 10 to 100%, particularly preferably 20 to 100%.

The proportion of the conductive particles P contained in the conductiveparts 22 for connection in the functional part 21 is preferably 10 to60%, more preferably 15 to 50% in terms of volume fraction. If thisproportion is lower than 10%, it may be impossible in some cases toobtain conductive parts 22 for connection having a sufficiently lowelectric resistance value. If this proportion exceeds 60% on the otherhand, the resulting conductive parts 22 for connection are liable to bebrittle, so that elasticity required of the conductive parts 22 forconnection may not be achieved in some cases.

The proportion of the conductive particles P contained in the parts 25to be supported varies according to the content of the conductiveparticles in the molding material for forming the elasticanisotropically conductive films 20. However, it is preferablyequivalent to or more than the proportion of the conductive particlescontained in the molding material in that the conductive particles P aresurely prevented from being contained in excess in the conductive parts22 for connection located most outside among the conductive parts 22 forconnection in the elastic anisotropically conductive film 20. It is alsopreferable that the proportion be at most 30% in terms of volumefraction in that parts 25 to be supported having sufficient strength areprovided.

The anisotropically conductive connector described above may beproduced, for example, in the following manner.

A frame plate 10 composed of a magnetic metal, in which anisotropicallyconductive film-arranging holes 11 have been formed corresponding to apattern of electrode regions, in which electrodes to be inspected havebeen formed, of integrated circuits in a wafer, which is an object ofinspection, is first produced. As a method for forming theanisotropically conductive film-arranging holes 11 in the frame plate10, may be used, for example, an etching method or the like.

A molding material for elastic anisotropically conductive films withconductive particles exhibiting magnetism dispersed in addition typeliquid silicone rubber is then prepared. As illustrated in FIG. 5, amold 60 for molding elastic anisotropically conductive films isprovided, and the molding material for elastic anisotropicallyconductive films is applied to the molding surfaces of a top force 61and a bottom force 65 in the mold 60 in accordance with a necessarypattern, namely, an arrangement pattern of elastic anisotropicallyconductive films to be formed, thereby forming molding material layers20A.

The mold 60 will be described specifically. This mold 60 is soconstructed that the top force 61 and the bottom force 65 making a pairtherewith are arranged so as to be opposed to each other.

In the top force 61, ferromagnetic substance layers 63 are formed inaccordance with a pattern antipodal to an arrangement pattern of theconductive parts 22 for connection in each of the elasticanisotropically conductive films 20 to be molded on the lower surface ofa base plate 62, and non-magnetic substance layers 64 are formed atother portions than the ferromagnetic substance layers 63 asillustrated, on an enlarged scale, in FIG. 6. A molding surface isformed by these ferromagnetic substance layers 63 and non-magneticsubstance layers 64.

In the bottom force 65 on the other hand, ferromagnetic substance layers67 are formed in accordance with the same pattern as the arrangementpattern of the conductive parts 22 for connection in the elasticanisotropically conductive films 20 to be molded on the upper surface ofa base plate 66, and non-magnetic substance layers 68 are formed atother portions than the ferromagnetic substance layers 67. A moldingsurface is formed by these ferromagnetic substance layers 67 andnon-magnetic substance layers 68.

Recessed parts 64 a and 68 a are formed in the molding surfaces of thetop force 61 and the bottom force 65, respectively, for formingfunctional parts 21 having a thickness greater than the thickness of theparts 25 to be supported.

The respective base plates 62 and 66 in the top force 61 and bottomforce 65 are preferably formed by a ferromagnetic substance. Specificexamples of such a ferromagnetic substance include ferromagnetic metalssuch as iron, iron-nickel alloys, iron-cobalt alloys, nickel and cobalt.The base plates 62, 66 preferably have a thickness of 0.1 to 50 mm, andsurfaces thereof are preferably smooth, subjected to a chemicaldegreasing treatment or mechanical polishing treatment.

As a material for forming the ferromagnetic substance layers 63, 67 inboth top force 61 and bottom force 65, may be used a ferromagnetic metalsuch as iron, iron-nickel alloy, iron-cobalt alloy, nickel or cobalt.The ferromagnetic substance layers 63, 67 preferably have a thickness ofat least 10 μm. When this thickness is at least 10 μm, a magnetic fieldhaving a sufficient intensity distribution can be applied to the moldingmaterial layers 20A. As a result, the conductive particles can begathered at a high density to portions to become conductive parts 22 forconnection in the molding material layers 20A, and so conductive parts22 for connection having good conductivity can be provided.

As a material for forming the non-magnetic substance layers 64, 68 inboth top force 61 and bottom force 65, may be used a non-magnetic metalsuch as copper, a polymeric substance having heat resistance, or thelike. However, a polymeric substance cured by magnetic waves maypreferably be used in that the non-magnetic substance layers 64, 68 canbe easily formed by a technique of photolithography. As a materialthereof, may be used, for example, a photoresist such as an acrylic typedry film resist, epoxy type liquid resist or polyimide type liquidresist.

As a method for coating the molding surfaces of the top force 61 andbottom force 65 with the molding material, may preferably be used ascreen printing method. According to such a method, the molding materialcan be easily applied according to the necessary pattern, and a properamount of the molding material can be applied.

As illustrated in FIG. 7, the frame plate 10 is then arranged inalignment on the molding surface of the bottom force 65, on which themolding material layers 20A have been formed, through a spacer 69 a, andon the frame plate 10, the top force 61, on which the molding materiallayers 20A have been formed, is arranged in alignment through a spacer69 b. These are superimposed on each other, whereby molding materiallayers 20A of the intended shape (shape of the elastic anisotropicallyconductive films 20 to be formed) are formed between the top force 61and the bottom force 65 as illustrated in FIG. 8. In each of thesemolding material layers 20A, the conductive particles P are contained ina state dispersed throughout in the molding material layer 20A asillustrated in FIG. 9.

The spacers 69 a and 69 b are arranged between the frame plate 10, andthe bottom force 65 and the top force 61, respectively as describedabove, whereby the elastic anisotropically conductive films of theintended shape can be formed, and adjoining elastic anisotropicallyconductive films are prevented from being connected to each other, sothat a great number of anisotropically conductive films independent ofone another can be formed with certainty.

A pair of, for example, electromagnets are then arranged on the uppersurface of the base plate 62 in the top force 61 and the lower surfaceof the base plate 66 in the bottom force 65, and the electromagnets areoperated, whereby a magnetic field having higher intensity at portionsbetween the ferromagnetic substance layers 63 of the top force 61 andtheir corresponding ferromagnetic substance layers 67 of the bottomforce 65 than surrounding regions thereof is formed because theferromagnetic substance layers 63, 67 of the top force 61 and bottomforce 65 function as magnetic poles. As a result, in the moldingmaterial layers 20A, the conductive particles P dispersed in the moldingmaterial layers 20A are gathered to portions to become the conductiveparts 22 for connection, which are located between the ferromagneticsubstance layers 63 of the top force 61 and their correspondingferromagnetic substance layers 67 of the bottom force 65, and orientedso as to align in the thickness-wise direction as illustrated in FIG.10. In the above-described process, since the frame plate 10 is composedof the magnetic metal, a magnetic field having higher intensity atportions between each of the top force 61 and the bottom force 65, andthe frame plate 10 than vicinities thereof is formed. As a result, theconductive particles P existing above and below the frame plate 10 inthe molding material layers 20A are not gathered between theferromagnetic substance layers 63 of the top force 61 and theferromagnetic substance layers 67 of the bottom force 65, but remainretained above and below the frame plate 10.

In this state, the molding material layers 20A are subjected to a curingtreatment, whereby the elastic anisotropically conductive films 20 eachcomposed of a functional part 21, in which a plurality of conductiveparts 22 for connection containing the conductive particles P in theelastic polymeric substance in a state oriented so as to align in thethickness-wise direction are arranged in a state mutually insulated byan insulating part 23 composed of the elastic polymeric substance, inwhich the conductive particles P are not present at all or scarcelypresent, and a part 25 to be supported, which is continuously andintegrally formed at a periphery of the functional part 21 and in whichthe conductive particles P are contained in the elastic polymericsubstance, are formed in a state that the part 25 to be supported hasbeen fixed to the periphery of each anisotropically conductivefilm-arranging hole 11 of the frame plate 10, thus producing ananisotropically conductive connector.

In the above-described process, the intensity of the external magneticfield applied to the portions to become the conductive parts 22 forconnection and the portions to become the parts 25 to be supported inthe molding material layers 20A is preferably an intensity that itamounts to 0.1 to 2.5 T on the average.

The curing treatment of the molding material layers 20A is suitablyselected according to the material used. However, the treatment isgenerally conducted by a heating treatment. When the curing treatment ofthe molding material layers 20A is conducted by heating, it is onlynecessary to provide a heater in an electromagnet. Specific heatingtemperature and heating time are suitably selected in view of the kindsof the polymeric substance-forming material for forming the moldingmaterial layers 20A, and the like, the time required for movement of theconductive particles P, and the like.

According to the above-described anisotropically conductive connector,since the part 25 to be supported is formed at the peripheral edge ofthe functional part 21 having the conductive parts 22 for connection ineach of the elastic anisotropically conductive films 20, and this part25 to be supported is fixed to the periphery about the anisotropicallyconductive film-arranging hole 11 in the frame plate 10, theanisotropically conductive connector is hard to be deformed and easy tohandle, so that the positioning and the holding and fixing to a wafer,which is an object of inspection, can be easily conducted in anelectrically connecting operation to the wafer.

In addition, since there is no difference in thickness between theconductive parts 22 for connection and the insulating part 23 in thefunctional part 21 of each of the elastic anisotropically conductivefilms 20, the mold used in the formation of the elastic anisotropicallyconductive films 20 has a flat molding surface, and so the movement ofthe conductive particles P is not inhibited when the magnetic field isapplied to the molding material layers 20A, and the conductive particlesP can be easily gathered to portions to become the conductive parts 22for connection almost without remaining at a portion to become theinsulating part in the molding material layers 20A. As a result, goodconductivity is surely achieved as to all the conductive parts 22 forconnection formed and sufficient insulating property is surely attainedbetween adjoining conductive parts 22 for connection.

Further, since there is no difference in height level between theconductive parts 22 for connection and the insulating part 23 in thesurface of the functional part 21 of each of the elastic anisotropicallyconductive films 20, the occurrence of permanent deformation of theconductive parts 22 for connection due to crush of the projected partsthereof is avoided even when a wafer, which is an object of inspection,has projected electrodes to be inspected, and so high durability inrepeated use is attained.

One flat surface of the functional part 21 in the elasticanisotropically conductive film 20 is formed so as to project from thepart 25 to be supported, and the ratio of the area of the one surfacesof the functional parts to the area of the front surface of the wafer,which is the object of inspection, falls within a specified range,whereby a load is applied concentratedly only to the functional partswhen the anisotropically conductive connector is pressurized in athickness-wise direction, so that good conductivity is surely achievedon the conductive parts 22 for connection even when pressurized under asmall load.

Since the respective anisotropically conductive film-arranging holes 11in the frame plate 10 are formed corresponding to the electrode regions,in which electrodes to be inspected have been formed, of integratedcircuits in a wafer, which is an object of inspection, and the elasticanisotropically conductive film 20 arranged in each of theanisotropically conductive film-arranging holes 11 may be small in area,the individual elastic anisotropically conductive films 20 are easy tobe formed. In addition, since the elastic anisotropically conductivefilm 20 small in area is little in the absolute quantity of thermalexpansion in a plane direction of the elastic anisotropically conductivefilm 20 even when it is subjected to thermal hysteresis, the thermalexpansion of the elastic anisotropically conductive film 20 in the planedirection is surely restrained by the frame plate 10 by using a materialhaving a low coefficient of linear thermal expansion as that for formingthe frame plate 10. Accordingly, a good electrically connected state canbe stably retained even when the WLBI test is performed on a large-areawafer.

Further, the frame plate 10 composed of a ferromagnetic substance isused, whereby the conductive particles P existing in the portions tobecome parts 25 to be supported in the molding material layer 20A, i.e.,the portions located above and below the peripheries about theanisotropically conductive film-arranging holes 11 in the frame plate 10are not gathered to the portions to become conductive parts 22 forconnection when the molding material layers 20A are subjected to thecuring treatment in a state that the conductive particles P have beenexisted in the portions to become the parts 25 to be supported in themolding material layers 20A by applying, for example, a magnetic fieldto said portions in the formation of the elastic anisotropicallyconductive films 20. As a result, the conductive particles P are surelyprevented from being contained in excess in the conductive parts 22 forconnection located most outside among the conductive parts 22 forconnection in the elastic anisotropically conductive film 20 thusobtained. Accordingly, there is no need to reduce the content of theconductive particles P in the molding material layers 20A, so that goodconductivity is surely achieved as to all the conductive parts 22 forconnection of the elastic anisotropically conductive film 20, andinsulating property between adjoining conductive parts 22 for connectionis surely attained.

Since the positioning holes 16 are formed in the frame plate 10,positioning to the wafer, which is the object of inspection, or thecircuit board for inspection can be easily conducted.

Since the air circulating holes 15 are formed in the frame plate 10, airexisting between the anisotropically conductive connector and thecircuit board for inspection is discharged through the air circulatingholes 15 in the frame plate 10 at the time the pressure within a chamberis reduced when that by the pressure reducing system is utilized as themeans for pressing the probe member in a wafer inspection apparatus,which will be described subsequently, whereby the anisotropicallyconductive connector can be surely brought into close contact with thecircuit board for inspection, so that the necessary electricalconnection can be achieved with certainty.

[Wafer Inspection Apparatus]

FIG. 11 is a cross-sectional view schematically illustrating theconstruction of an exemplary wafer inspection apparatus making use ofthe anisotropically conductive connector according to the presentinvention. This wafer inspection apparatus serves to perform electricalinspection of each of a plurality of integrated circuits formed on awafer in a state of the wafer.

The wafer inspection apparatus shown in FIG. 11 has a probe member 1 forconducting electrical connection of each of electrodes 7 to be inspectedof a wafer 6, which is an object of inspection, to a tester. As alsoillustrated on an enlarged scale in FIG. 12, the probe member 1 has acircuit board 30 for inspection, on the front surface (lower surface inFIG. 11) of which a plurality of inspection electrodes 31 have beenformed in accordance with a pattern corresponding to a pattern of theelectrodes 7 to be inspected of the wafer 6 that is the object ofinspection. On the front surface of the circuit board 30 for inspection,is provided the anisotropically conductive connector 2 of theconstruction illustrated in FIGS. 1 to 4 in such a manner that theconductive parts 22 for connection in the elastic anisotropicallyconductive films 20 of the connector are opposed to and brought intocontact with the inspection electrodes 31 of the circuit board 30 forinspection, respectively. On the front surface (lower surface in thefigure) of the anisotropically conductive connector 2, is provided asheet-like connector 40, in which a plurality of electrode structures 42have been arranged in an insulating sheet 41 in accordance with thepattern corresponding to the pattern of the electrodes 7 to be inspectedof the wafer 6, which is the object of inspection, in such a manner thatthe electrode structures 42 are opposed to and brought into contact withthe conductive parts 22 for connection in the elastic anisotropicallyconductive films 20 of the anisotropically conductive connector 2,respectively.

On the back surface (upper surface in the figure) of the circuit board30 for inspection in the probe member 1, is provided a pressurizingplate 3 for pressurizing the probe member 1 downward. A wafer mountingtable 4, on which the wafer 6 that is the object of inspection ismounted, is provided below the probe member 1. A heater 5 is connectedto each of the pressurizing plate 3 and the wafer mounting table 4.

As a base material for making up the circuit board 30 for inspection,may be used any of conventionally known various base materials. Specificexamples thereof include composite resin materials such as glassfiber-reinforced epoxy resins, glass fiber-reinforced phenol resins,glass fiber-reinforced polyimide resins and glass fiber-reinforcedbismaleimidotriazine resins, and ceramic materials such as glass,silicon dioxide and alumina.

When a wafer inspection apparatus for conducting the WLBI test isconstructed, a material having a coefficient of linear thermal expansionof at most 3×10⁻⁵/K, more preferably 1×10⁻⁷ to 1×10⁻⁵/K, particularlypreferably 1×10⁻⁶ to 6×10⁻⁶/K is preferably used.

Specific examples of such a base material include Pyrex (trademark)glass, quartz glass, alumina, beryllia, silicon carbide, aluminumnitride and boron nitride.

The sheet-like connector 40 in the probe member 1 will be describedspecifically. This sheet-like connector 40 has a flexible insulatingsheet 41, and in this insulating sheet 41, a plurality of electrodestructures 42 extending in a thickness-wise direction of the insulatingsheet 41 and composed of a metal are arranged in a state separated fromeach other in a plane direction of the insulating sheet 41 in accordancewith the pattern corresponding to the pattern of the electrodes 7 to beinspected of the wafer 6 that is the object of inspection.

Each of the electrode structures 42 is formed by integrally connecting aprojected front-surface electrode part 43 exposed to the front surface(lower surface in the figure) of the insulating sheet 41 and aplate-like back-surface electrode part 44 exposed to the back surface ofthe insulating sheet 41 to each other by a short circuit part 45extending through in the thickness-wise direction of the insulatingsheet 41.

No particular limitation is imposed on the insulating sheet 41 so far asit has insulating property and is flexible. For example, a resin sheetformed of a polyamide resin, liquid crystal polymer, polyester,fluororesin or the like, or a sheet obtained by impregnating a clothwoven by fibers with any of the above-described resins may be used.

No particular limitation is also imposed on the thickness of theinsulating sheet 41 so far as such an insulating sheet 41 is flexible.However, it is preferably 10 to 50 μm, more preferably 10 to 25 μm.

As a metal for forming the electrode structures 42, may be used nickel,copper, gold, silver, palladium, iron or the like. The electrodestructures 42 may be any of those formed of a simple metal as a whole,those formed of an alloy of at least two metals and those obtained bylaminating at least two metals.

On the surfaces of the front-surface electrode part 43 and back-surfaceelectrode part 44 in the electrode structure 42, a film of a chemicallystable metal having high conductivity, such as gold, silver or palladiumis preferably formed in that oxidation of the electrode parts isprevented, and electrode parts small in contact resistance are obtained.

The projected height of the front-surface electrode part 43 in theelectrode structure 42 is preferably 15 to 50 μm, more preferably 15 to30 μm in that stable electrical connection to the electrode 7 to beinspected of the wafer 6 can be achieved. The diameter of thefront-surface electrode part 43 is preset according to the size andpitch of the electrodes to be inspected of the wafer 6 and is, forexample, 30 to 80 μm, preferably 30 to 50 μm.

It is only necessary for the diameter of the back-surface electrode part44 in the electrode structure 42 to be greater than the diameter of theshort circuit part 45 and smaller than the arrangement pitch of theelectrode structures 42, and the diameter is preferably great as much aspossible, whereby stable electrical connection also to the conductivepart 22 for connection in the elastic anisotropically conductive film 20of the anisotropically conductive connector 2 can be achieved withcertainty. The thickness of the back-surface electrode part 44 ispreferably 20 to 50 μm, more preferably 35 to 50 μm in that the strengthis sufficiently high, and excellent repetitive durability is achieved.

The diameter of the short circuit part 45 in the electrode structure 42is preferably 30 to 80 μm, more preferably 30 to 50 μm in thatsufficiently high strength is achieved.

The sheet-like connector 40 can be produced, for example, in thefollowing manner.

Namely, a laminate material obtained by laminating a metal layer on aninsulating sheet 41 is provided, and a plurality of through-holesextending through in the thickness-wise direction of the insulatingsheet 41 are formed in the insulating sheet 41 of the laminate materialin accordance with a pattern corresponding to a pattern of electrodestructures 42 to be formed by laser machining, wet etch machining, dryetch machining or the like. This laminate material is then subjected tophotolithography and a plating treatment, whereby short circuit parts 45integrally connected to the metal layer are formed in the through-holesin the insulating sheet 41, and at the same time, projectedfront-surface electrode parts 43 integrally connected to the respectiveshort circuit parts 45 are formed on a front surface of the insulatingsheet 41. Thereafter, the metal layer of the laminate material issubjected to a photo-etching treatment to remove a part thereof, therebyforming back-surface electrode parts 44 to form the electrode structures42, thus obtaining the sheet-like connector 40.

In such an electrical inspection apparatus, a wafer 6, which is anobject of inspection, is mounted on the wafer mounting table 4, and theprobe member 1 is then pressurized downward by the pressurizing plate 3,whereby the respective front-surface electrode parts 43 in the electrodestructures 42 of the sheet-like connector 40 thereof are brought intocontact with their corresponding electrodes 7 to be inspected of thewafer 6, and further the respective electrodes 7 to be inspected of thewafer 6 are pressurized by the front-surface electrodes parts 43. Inthis state, each of the conductive parts 22 for connection in theelastic anisotropically conductive films 20 of the anisotropicallyconductive connector 2 are respectively held and pressurized by theinspection electrodes 31 of the circuit board 30 for inspection and thefront-surface electrode parts 43 of the electrode structures 42 of thesheet-like connector 40 and compressed in the thickness-wise direction,whereby conductive paths are formed in the respective conductive parts22 for connection in the thickness-wise direction thereof. As a result,electrical connection between the electrodes 7 to be inspected of thewafer 6 and the inspection electrodes 31 of the circuit board 30 forinspection is achieved. Thereafter, the wafer 6 is heated to apredetermined temperature through the wafer mounting table 4 and thepressurizing plate 3 by the heater 5. In this state, necessaryelectrical inspection is performed as to the each of a plurality ofintegrated circuits in the wafer 6.

According to such a wafer inspection apparatus, electrical connection tothe electrodes 7 to be inspected of the wafer 6, which is the object ofinspection, is achieved through the probe member 1 having theabove-described anisotropically conductive connector 2. Therefore,positioning, and holding and fixing to the wafer can be conducted withease even when the pitch of the electrodes 7 to be inspected is small.In addition, high reliability on connection to the respective electrodesto be inspected is achieved because the conductive parts 22 forconnection of the elastic anisotropically conductive films 20 in theanisotropically conductive connector 2 have good conductivity, andinsulating property between adjoining conductive parts 22 for connectionis sufficiently secured, and moreover the necessary electricalinspection can be stably performed over a long period of time even whenthe inspection is conducted repeatedly.

Since each of the elastic anisotropically conductive films 20 in theanisotropically conductive connector 2 is small in its own area, and theabsolute quantity of thermal expansion in a plane direction of theelastic anisotropically conductive film 20 is little even when it issubjected to thermal hysteresis, the thermal expansion of the elasticanisotropically conductive film 20 in the plane direction is surelyrestrained by the frame plate by using a material having a lowcoefficient of linear thermal expansion as that for forming the frameplate 10. Accordingly, a good electrically connected state can be stablyretained even when the WLBI test is performed on a large-area wafer.

FIG. 13 is a cross-sectional view schematically illustrating theconstruction of another exemplary wafer inspection apparatus making useof the anisotropically conductive connector according to the presentinvention, and FIG. 14 is a cross-sectional view illustrating, on anenlarged scale, the construction of a probe member in the waferinspection apparatus shown in FIG. 13.

This wafer inspection apparatus has a box-type chamber 50 opened at thetop thereof, in which a wafer 6 that is an object of inspection ishoused. An evacuation pipe 51 for evacuating air within the chamber 50is provided in a sidewall of this chamber 50, and an evacuator (notillustrated) such as, for example, a vacuum pump, is connected to theevacuation pipe 51.

A probe member 1 of the same construction as the probe member 1 in thewafer inspection apparatus shown in FIG. 11 is arranged on the chamber50 so as to air-tightly close the opening of the chamber 50. Morespecifically, an elastic O-ring 55 is arranged in close contact on anupper end surface of the sidewall in the chamber 50, and the probemember 1 is arranged in a state that the anisotropically conductiveconnector 2 and sheet-like connector 40 thereof have been housed in thechamber 50, and the periphery of the circuit board 30 for inspectionthereof has been brought into close contact with the O-ring 55. Further,the circuit board 30 for inspection is held in a state pressurizeddownward by a pressurizing plate 3 provided on the back surface (uppersurface in FIG. 13) thereof.

A heater 5 is connected to the chamber 50 and the pressurizing plate 3.

In such a wafer inspection apparatus, the evacuator (not illustrated)connected to the evacuation pipe 51 of the chamber 50 is driven, wherebythe pressure within the chamber 50 is reduced to, for example, 1,000 Paor lower. As a result, the probe member 1 is pressurized downward by theatmospheric pressure, whereby the O-ring 55 is elastically deformed, andso the probe member 1 is moved downward. As a result, the electrodes 7to be inspected of the wafer 6 are respectively pressurized by theircorresponding front-surface electrode parts 43 in the electrodestructures 42 of the sheet-like connector 40. In this state, theconductive parts 22 for connection in the elastic anisotropicallyconductive films 20 of the anisotropically conductive connector 2 arerespectively held and pressurized by the inspection electrodes 31 of thecircuit board 30 for inspection and the front-surface electrode parts 43in the electrode structures 42 of the sheet-like connector 40 andcompressed in the thickness-wise direction, whereby conductive paths areformed in the respective conductive parts 22 for connection in thethickness-wise direction thereof. As a result, electrical connectionbetween the electrodes 7 to be inspected of the wafer 6 and theinspection electrodes 31 of the circuit board 30 for inspection isachieved. Thereafter, the wafer 6 is heated to a predeterminedtemperature through the chamber 50 and the pressurizing plate 3 by theheater 5. In this state, necessary electrical inspection is performed oneach of a plurality of integrated circuits in the wafer 6.

According to such a wafer inspection apparatus, the same effects asthose in the wafer inspection apparatus shown in FIG. 11 are broughtabout. In addition, the whole inspection apparatus can be miniaturizedbecause any large-sized pressurizing mechanism is not required, andmoreover the whole wafer 6, which is the object of inspection, can bepressed by even force even when the wafer 6 has a large area of, forexample, 8 inches or greater in diameter. In addition, since the aircirculating holes 15 are formed in the frame plate 10 in theanisotropically conductive connector 2, air existing between theanisotropically conductive connector 2 and the circuit board 30 forinspection is discharged through the air circulating holes 15 of theframe plate 10 in the anisotropically conductive connector 2 when thepressure within the chamber 50 is reduced, whereby the anisotropicallyconductive connector 2 can be surely brought into close contact with thecircuit board 30 for inspection, so that the necessary electricalconnection can be achieved with certainty.

Other Embodiments

The present invention is not limited to the above-described embodiments,and the following various changes or modifications may be added thereto.

(1) In the anisotropically conductive connector according to the presentinvention, conductive parts for non-connection that are not electricallyconnected to any electrode to be inspected in a wafer may be formed inthe elastic anisotropically conductive films 20 in addition to theconductive parts 22 for connection. An anisotropically conductiveconnector having anisotropically conductive films, in which theconductive parts for non-connection have been formed, will hereinafterbe described.

FIG. 15 is a plan view illustrating, on an enlarged scale, an elasticanisotropically conductive film in an anisotropically conductiveconnector according to another embodiment of the present invention, andFIG. 16 is a cross-sectional view illustrating, on an enlarged scale,the elastic anisotropically conductive film in the anisotropicallyconductive connector shown in FIG. 15. In the elastic anisotropicallyconductive film 20 of this anisotropically conductive connector, aplurality of conductive parts 22 for connection that are electricallyconnected to electrodes to be inspected in a wafer, which is an objectof inspection, and extend in the thickness-wise direction (directionperpendicular to the paper in FIG. 15) are arranged so as to align in aline in accordance with a pattern corresponding to a pattern of theelectrodes to be inspected. Each of these conductive parts 22 forconnection contains conductive particles exhibiting magnetism at a highdensity in a state oriented so as to align in the thickness-wisedirection and are mutually insulated by an insulating part 23, in whichthe conductive particles are not contained at all or scarcely contained.

Two conductive parts 22 for connection adjoining each other and locatedat the center among these conductive parts 22 for connection arearranged at a clearance greater than a clearance between otherconductive parts 22 for connection adjoining each other. A conductivepart 26 for non-connection that is not electrically connected to anyelectrode to be inspected in the wafer, which is the object ofinspection, and extend in the thickness-wise direction is formed betweenthe two conductive parts 22 for connection adjoining each other andlocated at the center. Further, conductive parts 26 for non-connectionthat are not electrically connected to any electrode to be inspected inthe wafer, which is the object of inspection, and extend in thethickness-wise direction are formed between the conductive parts 22 forconnection located most outside in a direction that the conductive parts22 for connection are arranged and the frame plate 10. These conductiveparts 26 for non-connection contain the conductive particles exhibitingmagnetism at a high density in a state oriented so as to align in thethickness-wise direction and are mutually insulated from the conductiveparts 22 for connection by an insulating part 23, in which theconductive particles are not contained at all or scarcely contained.

At the peripheral edge of the functional part 21, a part 25 to besupported that is fixed to and supported by the peripheral edge aboutthe anisotropically conductive film-arranging hole 11 in the frame plate10 is formed integrally and continuously with the functional part 21,and the conductive particles are contained in this part 25 to besupported.

Other constitutions are basically the same as those in theanisotropically conductive connector shown in FIGS. 1 to 4.

The anisotropically conductive connector shown in FIGS. 15 and 16 can beproduced in a similar manner to the process for producing theanisotropically conductive connector shown in FIGS. 1 to 4 by using amold composed of a top force and a bottom force, on which ferromagneticsubstance layers have been respectively formed in accordance with apattern corresponding to an arrangement pattern of the conductive parts22 for connection and conductive parts 26 for non-connection in theelastic anisotropically conductive films 20 to be formed, andnon-magnetic substance layers have been formed at other portions thanthe ferromagnetic substance layers, in place of the mold shown in FIG.6.

More specifically, according to such a mold, a pair of, for example,electromagnets are arranged on an upper surface of a base plate in thetop force and a lower surface of a base plate in the bottom force, andthe electromagnets are operated, whereby in molding material layersformed between the top force and the bottom force, conductive particlesdispersed in portions to become the functional parts 21 in the moldingmaterial layers are gathered to portions to become the conductive parts22 for connection and the portions to become the conductive parts 26 fornon-connection, and oriented so as to align in the thickness-wisedirection. On the other hand, the conductive particles located above andbelow the frame plate 10 in the molding material layers remain retainedabove and below the frame plate 10.

In this state, the molding material layers are subjected to a curingtreatment, whereby the elastic anisotropically conductive films 20 eachcomposed of the functional part 21, in which a plurality of theconductive parts 22 for connection and the conductive parts 26 fornon-connection, in which the conductive particles are contained in theelastic polymeric substance in a state oriented so as to align in thethickness-wise direction, are arranged in a state mutually insulated bythe insulating part 23 composed of the elastic polymeric substance, inwhich the conductive particles are not present at all or scarcelypresent, and the part 25 to be supported, which is continuously andintegrally formed at a peripheral edge of the functional part 21 and inwhich the conductive particles are contained in the elastic polymericsubstance, are formed in a state that the part 25 to be supported hasbeen fixed to the periphery about each anisotropically conductivefilm-arranging hole 11 of the frame plate 10, thus producing theanisotropically conductive connector.

The conductive parts 26 for non-connection in the anisotropicallyconductive connector shown in FIG. 15 are obtained by applying amagnetic field to portions to become the conductive parts 26 fornon-connection in each of the molding material layers in the formationof the elastic anisotropically conductive films 20, thereby gatheringthe conductive particles existing between the two adjoining portionsarranged at the greater clearance in the molding material layer, whichwill become the conductive parts 22 for connection, and the conductiveparticles existing between the portions located most outside in themolding material layer, which will become the conductive parts 22 forconnection, and the frame plate 10 to the portions to become theconductive parts 26 for non-connection, and subjecting the moldingmaterial layers to a curing treatment in this state. Thus, theconductive particles are prevented from being gathered in excess to thetwo adjoining portions arranged at the greater clearance in the moldingmaterial layer, which will become the conductive parts 22 forconnection, and the portions located most outside in the moldingmaterial layer, which will become the conductive parts 22 forconnection. Accordingly, even when the elastic anisotropicallyconductive films 20 to be formed each have at least two conductive parts22 for connection arranged at a greater clearance, it is surelyprevented for these conductive parts 22 for connection to contain anexcessive amount of the conductive particles. In addition, even when theelastic anisotropically conductive films 20 to be formed have acomparatively great number of conductive parts 22 for connection, it issurely prevented for the conductive parts 22 for connection located mostoutside in the elastic anisotropically conductive film 20 to contain anexcessive amount of the conductive particles.

(2) In the anisotropically conductive connector according to the presentinvention, projected parts 24 that the conductive parts 22 forconnection and peripheral portions thereof protrude from the surface ofany other portion may be formed on one surface of the functional part 21of the elastic anisotropically conductive film 20 as illustrated in FIG.17, or projected parts 24 that the conductive parts 22 for connectionand peripheral portions thereof protrude from the surface of any otherportion may be formed on both surfaces of the functional part 21 of theelastic anisotropically conductive film 20 so far as a ratio of thethickness of the insulating part 23 to the thickness of the conductiveparts 22 for connection in the functional part 21 of the elasticanisotropically conductive film 20 is at least 0.9

(3) In the anisotropically conductive connector according to the presentinvention, a metal layer may be formed on the surfaces of the conductiveparts 22 for connection in the elastic anisotropically conductive films20.

(4) In the anisotropically conductive connector according to the presentinvention, a DLC layer may be formed on the surfaces of the elasticanisotropically conductive film 20.

(5) When a non-magnetic substance is used as a base material of theframe plate 10 in the production of the anisotropically conductiveconnector according to the present invention, as a method for applyingthe magnetic field to portions to become the parts 25 to be supported inthe molding material layers 20A, a means of plating peripheral portionsof the anisotropically conductive film-arranging holes 11 in the frameplate 10 with a magnetic substance or coating them with a magnetic paintto apply a magnetic field thereto, or a means of forming ferromagneticsubstance layers on the mold 60 corresponding to the parts 25 to besupported of the elastic anisotropically conductive films 20 to apply amagnetic field thereto may be utilized.

(6) The use of the spacers is not essential in the formation of themolding material layers, and spaces for forming the elasticanisotropically conductive films may be secured between the top forceand bottom force, and the frame plate by any other means.

(7) In the wafer inspection apparatus according to the presentinvention, the sheet-like connector in the probe member is notessential, and the wafer inspection apparatus may be so constructed thatthe elastic anisotropically conductive films 20 in the anisotropicallyconductive connector 2 are brought into contact with a wafer, which isan object of inspection, to achieve electrical connection as illustratedin FIGS. 18 and 19.

(8) The anisotropically conductive connector according to the presentinvention or the probe member according to the present invention mayalso be used in inspection of a wafer 6, on which integrated circuitshaving projected electrodes (bumps) formed of gold, solder or the likehave been formed as the electrodes 7 to be inspected, as illustrated inFIGS. 20 and 21, in addition to the inspection of a wafer, on whichintegrated circuits having flat electrodes composed of aluminum havebeen formed.

Since the electrode formed of gold, solder or the like is resistive to aformation of an oxidized film on the surface thereof compared with theelectrode composed of aluminum, there is no need of pressurizing suchelectrodes under a heavy load required for breaking through the oxidizedfilm in the inspection of the wafer 6, on which the integrated circuithaving such projected electrodes as electrodes 7 to be inspected havebeen formed, and the inspection can be performed in a state that theconductive parts 22 for connection in the anisotropically conductiveconnector 2 have been brought into direct contact with the electrodes 7to be inspected without using any sheet-like connector.

When inspection of a wafer is conducted in a state that conductive partsfor connection of an anisotropically conductive connector have beenbrought into direct contact with projected electrodes, which areelectrodes to be inspected, the conductive parts for connection undergoabrasion or permanent compressive deformation by being pressurized withthe projected electrodes when the anisotropically conductive connectoris used repeatedly. As a result, increase in electric resistance andconnection failure to the electrodes to be inspected occur on theconductive parts for connection, so that it has been necessary toreplace the anisotropically conductive connector by a new one at a highfrequency.

According to the anisotropically conductive connector according to thepresent invention or the probe member according to the presentinvention, however, the necessary conductivity is retained over a longperiod of time even when the wafer 6, which is an object of inspection,is a wafer having a diameter of 8 inches or 12 inches, on whichintegrated circuits have been formed at a high degree of integration,and the electrodes 7 to be inspected are projected electrodes, since theanisotropically conductive connector or probe member is high indurability in repeated use, whereby the frequency of replacing theanisotropically conductive connector by a new one becomes low, and sothe inspection cost can be reduced.

(9) In the anisotropically conductive connector according to the presentinvention, the anisotropically conductive film-arranging holes in theframe plate thereof may be formed corresponding to electrode regions, inwhich electrodes to be inspected have been arranged in a part ofintegrated circuits formed on a wafer, which is an object of inspection,and the elastic anisotropically conductive films may be arranged inthese anisotropically conductive film-arranging holes.

According to such an anisotropically conductive connector, a wafer canbe divided into two or more areas to collectively perform the probe teston integrated circuits formed in each of the divided areas.

More specifically, it is not essential to collectively performinspection on all the integrated circuits formed on the wafer in theinspection method for wafers using the anisotropically conductiveconnector according to the present invention or the probe memberaccording to the present invention.

In the burn-in test, inspection time required of each of integratedcircuits is as long as several hours, and so high time efficiency can beachieved when the inspection is conducted collectively on all integratedcircuits formed on a wafer. In the probe test on the other hand,inspection time required of each of integrated circuits is as short asseveral minutes, and so sufficiently high time efficiency can beachieved even when a wafer is divided into 2 or more areas, and theprobe test is conducted collectively on integrated circuits formed ineach of the divided areas.

As described above, according to the method that electrical inspectionis conducted every divided area as to integrated circuits formed on awafer, when the electrical inspection is conducted as to integratedcircuits formed at a high degree of integration on a wafer having adiameter of 8 inches or 12 inches, the numbers of inspection electrodesand wirings of the circuit board for inspection used can be reducedcompared with the method that the inspection is conducted collectivelyon all the integrated circuits, whereby the production cost of theinspection apparatus can be reduced.

Since the anisotropically conductive connector according to the presentinvention or the probe member according to the present invention is highin durability in repeated use, the frequency of occurrence of troublewith the anisotropically conductive connector and replacement of thesame by a new one become low when it is used in the method that theelectrical inspection is conducted, as to the integrated circuits formedon a wafer, in every divided area, so that inspection cost can bereduced.

(10) In the anisotropically conductive connector according to thepresent invention, it is not essential to form the parts 25 to besupported, which are stacked against the frame plate 10 as illustratedin FIG. 4, but the elastic anisotropically conductive film 20 may besupported by the frame plate 10 by bonding a side surface of the elasticanisotropically conductive film 20 to an inner surface of theanisotropically conductive film-arranging hole 11 in the frame plate 10as illustrated in FIG. 22.

In order to obtain such an anisotropically conductive connector, it isonly necessary to form a molding material layers without arrangingspacers between the top force and bottom force, and the frame plate in astep of forming the elastic anisotropically conductive films 20.

In such an anisotropically conductive connector, there is no need ofarranging spacers between the top force and bottom force, and the frameplate upon the formation of the elastic anisotropically conductive films20, and the intended thickness of the elastic anisotropically conductivefilms 20 is determined by the thickness of the frame plate 10 and thedepth of the recessed parts formed in the molding surfaces of the mold,so that it is easy to form thin elastic anisotropically conductive films20 having a thickness of, for example, 100 μm or less.

The present invention will hereinafter be described specifically by thefollowing examples. However, the present invention is not limited tothese examples.

[Production of Wafer for Evaluation]

As illustrated in FIG. 23, 393 square integrated circuits L in total,which each had dimensions of 8 mm×8 mm, were formed on a wafer 6 made ofsilicon (coefficient of linear thermal expansion: 3.3×10⁻⁶/K) and havinga diameter of 8 inches. Each of the integrated circuits L formed on thewafer 6 has a region A of electrodes to be inspected at its center asillustrated in FIG. 24. In the region A of the electrodes to beinspected, as illustrated in FIG. 25, 50 rectangular electrodes 7 to beinspected each having dimensions of 200 μm in a vertical direction(upper and lower direction in FIG. 25) and 50 μm in a lateral direction(left and right direction in FIG. 25) are arranged at a pitch of 100 μmin a line in the lateral direction. The total number of the electrodes 7to be inspected in the whole wafer 6 is 19,650. All the electrodes to beinspected are electrically connected to a common lead electrode (notillustrated) formed at a peripheral edge of the wafer 6. An area S2 of asurface of the wafer 6 on a side that the electrodes 7 to be inspectedhave been formed is 3.14×10⁴ mm². This wafer will hereinafter bereferred to as “Wafer W1 for evaluation”.

Further, 393 integrated circuits (L), which had the same construction asin the Wafer W1 for evaluation except that no common lead electrode wasformed as to 50 electrodes (7) to be inspected in the integrated circuit(L), and the electrodes to be inspected were electrically insulated fromone another, were formed on a wafer (6). The total number of theelectrodes to be inspected in the whole wafer is 19,650. An area S2 of asurface of the wafer (6) on a side that the electrodes (7) to beinspected have been formed is 3.14×10⁴ mm². This wafer will hereinafterbe referred to as “Wafer W2 for evaluation”.

[Production of Wafer for Test]

On a wafer (6), 393 integrated circuits (L), which had the sameconstruction as in the Wafer W1 for evaluation except that every twoelectrodes (7) to be inspected were electrically connected to each otheron every other electrode counting from an endmost electrode (7) to beinspected among 50 electrodes (7) to be inspected in the integratedcircuit (L), and no lead electrode was formed, were formed. The totalnumber of the electrodes to be inspected in the whole wafer is 19,650.Hereinafter, the total number of electrodes to be inspected in the wholewafer is 19,650. An area S2 of a surface of the wafer (6) on a side thatthe electrodes (7) to be inspected have been formed is 3.14×10⁴ mm².This wafer will hereinafter be referred to as “Wafer W3 for test”.

Further, 393 integrated circuits (L), which had the same construction asin the Wafer W1 for evaluation except that every two electrodes (7) tobe inspected were electrically connected to each other on every otherelectrode counting from an endmost electrode (7) to be inspected among50 electrodes (7) to be inspected in the integrated circuit (L), no leadelectrode was formed, and the electrodes to be inspected were changed toprojected electrodes having a diameter of 70 μm and a height of 30 μm,were formed on a wafer (6). The total number of the electrodes to beinspected in the whole wafer is 19,650. An area S2 of a surface of thewafer (6) on a side that the electrodes (7) to be inspected have beenformed is 3.14×10⁴ mm². This wafer will hereinafter be referred to as“Wafer W4 for test”.

EXAMPLES OF COMPARATIVE EXAMPLES

(1) Preparation of Conductive Particles:

Into a treating vessel of a powder plating apparatus, were poured 100 gof particles composed of nickel (saturation magnetization: 0.6 Wb/m²)and having a number average particle diameter of 10 μm, and 2 L of 0.32Nhydrochloric acid were further added. The resultant mixture was stirredto obtain a slurry containing core particles. This slurry was stirred atordinary temperature for 30 minutes, thereby conducting an acidtreatment of the core particles. Thereafter, the slurry thus treated wasleft at rest for 1 minute to precipitate the core particles, and asupernatant was removed.

To the core particles subjected to the acid treatment, were added 2 L ofpurified water, and the mixture was stirred for 2 minutes at ordinarytemperature. The mixture was then left at rest for 1 minute toprecipitate magnetic core particles, and a supernatant was removed. Thisprocess was conducted repeatedly twice, thereby conducting a washingtreatment of core particles.

To the core particles subjected to the acid treatment and washingtreatment, were added 2 L of a gold plating solution containing gold ina proportion of 20 g/L. The temperature in the treating vessel wasraised to 90° C. and the mixture was stirred, thereby preparing aslurry. While stirring the slurry in this state, the core particles weresubjected to displacement plating with gold. Thereafter, the slurry wasleft at rest while allowing it to cool, thereby precipitating particles,and a supernatant was removed to prepare conductive particles with thesurfaces of the core particles composed of nickel plated with gold.

To the conductive particles obtained in such a manner, were added 2 L ofpurified water, and the mixture was stirred at ordinary temperature for2 minutes. Thereafter, the mixture was left at rest for 1 minute toprecipitate the conductive particles, and a supernatant was removed.This process was repeated additionally twice, 2 L of purified waterheated to 90° C. were then added to the particles, and the mixture wasstirred. The resultant slurry was filtered through filter paper tocollect the conductive particles. The conductive particles weresubjected to a drying treatment by means of a dryer preset to 90° C.

An air classifier “Turboclassifier TC-15N” (manufactured by NisshinEngineering Co., Ltd.) was then used to subject 200 g of the conductiveparticles to a classification treatment under conditions of a specificgravity of 8.9, an air flow of 2.5 m³/min, a rotor speed of 1,600 rpm, aclassification point of 25 μm and a feed rate of the conductiveparticles of 16 g/min, thereby collecting 180 g of conductive particles.Further, 180 g of the conductive particles were subjected to anotherclassification treatment under conditions of a specific gravity of 8.9,an air flow of 25 m³/min, a rotor speed of 3,000 rpm, a classificationpoint of 10 μm and a feed rate of the conductive particles of 14 g/minto collect 150 g of conductive particles.

The conductive particles thus obtained were such that the number averageparticle diameter was 8.7 μm, the weight average particle diameter was9.9 μm, the ratio Dw/Dn value was 1.1, the standard deviation of theparticle diameter was 2.0, the coefficient of variation of the particlediameter was 23%, and the proportion of gold to the core particles was30% by mass. The conductive particles are referred to as “ConductiveParticles (a)”.

(2) Production of Frame Plate:

Twenty frame plates in total, each having a diameter of 8 inches and 393anisotropically conductive film-arranging holes formed corresponding tothe respective regions of the electrodes to be inspected in Wafer W1 forevaluation, were produced under the following conditions in accordancewith the construction shown in FIGS. 26 and 27.

A material of this frame plate 10 is covar (saturation magnetization:1.4 Wb/m²; coefficient of linear thermal expansion: 5×10⁻⁶/K), and thethickness thereof is 50 μm.

Each of the anisotropically conductive film-arranging holes 11 hasdimensions of 5,500 μm in a lateral direction (left and right directionin FIGS. 26 and 27) and 320 μm in a vertical direction (upper and lowerdirection in FIGS. 26 and 27).

A circular air circulating hole 15 is formed at a central positionbetween anisotropically conductive film-arranging holes 11 adjoining inthe vertical direction, and the diameter thereof is 1,000 μm.

(3) Production of Spacer:

Two spacers for molding elastic anisotropically conductive films, whicheach have a plurality of through-holes formed corresponding to theregions of the electrodes to be inspected in Wafer W1 for evaluation,were produced under the following conditions. A material of thesespacers is stainless steel (SUS304), and the thickness thereof is 10 μm.

The through-hole corresponding to each region of the electrodes to beinspected has dimensions of 6,000 μm in the lateral direction and 1,200μm in the vertical direction.

(4) Production of Mold:

A mold (K1) for molding elastic anisotropically conductive films wasproduced under the following conditions in accordance with theconstruction shown in FIGS. 7 and 28.

A top force 61 and a bottom force 65 in this mold (K1) respectively havebase plates 62 and 66 made of iron and each having a thickness of 6 mm.On the base plates 62 and 66, ferromagnetic substance layers 63 (67) forforming conductive parts for connection and ferromagnetic substancelayers 63 a (67 a) for forming conductive parts for non-connection,which are made of nickel, are arranged in accordance with a patterncorresponding to a pattern of the electrodes to be inspected in Wafer W1for evaluation. More specifically, the dimensions of each of theferromagnetic substance layers 63 (67) for forming conductive parts forconnection are 40 μm (lateral direction)×200 μm (vertical direction)×100μm (thickness), and 50 ferromagnetic substance layers 63 (67) arearranged at a pitch of 100 μm in a line in the lateral direction. Theferromagnetic substance layers 63 a (67 a) for forming conductive partsfor non-connection are arranged outside the ferromagnetic substancelayers 63 (67) located most outside in a direction that theferromagnetic substance layers 63 (67) are arranged. The dimensions ofeach of the ferromagnetic substance layers 63 a (67 a) are 40 μm(lateral direction)×200 μm (vertical direction)×100 μm (thickness).

Corresponding to the regions of the electrodes to be inspected in WaferW1 for evaluation, are formed 393 regions in total, in each of which 50ferromagnetic substance layers 63 (67) for forming conductive parts forconnection and 2 ferromagnetic substance layers 63 a (67 a) for formingconductive parts for non-connection have been formed. In the whole baseplate, are formed 19,650 ferromagnetic substance layers 63 (67) forforming conductive parts for connection and 786 ferromagnetic substancelayers 63 a (67 a) for forming conductive parts for non-connection.Non-magnetic substance layers 64 (68) are formed by subjecting a dryfilm resists to a curing treatment. The dimensions of each of recessedparts 64 a (68 a) for forming functional parts are 5,250 μm (lateraldirection)×210 μm (vertical direction)×25 μm (depth), and the thicknessof other portions than the recessed parts is 125 μm (the thickness ofthe recessed parts: 100 μm).

A mold (K2) for molding elastic anisotropically conductive films wasproduced under the following conditions in accordance with theconstruction shown in FIGS. 29 and 30.

A top force 61 and a bottom force 65 in this mold (K2) respectively havebase plates 62 and 66 made of iron and each having a thickness of 6 mm.On the base plates 62 and 66, ferromagnetic substance layers 63 (67) forforming conductive parts for connection and ferromagnetic substancelayers 63 a (67 a) for forming conductive parts for non-connection,which are made of nickel, are arranged in accordance with a patterncorresponding to a pattern of the electrodes to be inspected in Wafer W1for evaluation. More specifically, the dimensions of each of theferromagnetic substance layers 63 (67) for forming conductive parts forconnection are 40 μm (lateral direction)×200 μm (vertical direction)×100μm (thickness), and 50 ferromagnetic substance layers 63 (67) arearranged at a pitch of 100 μm in a line in the lateral direction. Theferromagnetic substance layers 63 a (67 a) for forming conductive partsfor non-connection are arranged outside the ferromagnetic substancelayers 63 (67) located most outside in a direction that theferromagnetic substance layers 63 (67) are arranged. The dimensions ofeach of the ferromagnetic substance layers 63 a (67 a) are 40 μm(lateral direction)×200 μm (vertical direction)×100 μm (thickness).

Corresponding to the regions of the electrodes to be inspected in WaferW1 for evaluation, are formed 393 regions in total, in each of which 50ferromagnetic substance layers 63 (67) for forming conductive parts forconnection and 2 ferromagnetic substance layers 63 a (67 a) for formingconductive parts for non-connection have been formed. In the whole baseplate, are formed 19,650 ferromagnetic substance layers 63 (67) forforming conductive parts for connection and 786 ferromagnetic substancelayers 63 a (67 a) for forming conductive parts for non-connection.Non-magnetic substance layers 64 (68) are formed by subjecting a dryfilm resists to a curing treatment. At regions, in which theferromagnetic substance layers 63 (67) for forming conductive parts forconnection are located, and regions, in which the ferromagneticsubstance layers 63 a (67 a) for forming conductive parts fornon-connection are located, are formed recessed parts 64 b (68 b) and 64c (68 c) for forming projected parts on an elastic anisotropicallyconductive film. The dimensions of each of the recessed parts 64 b (68b), at which the ferromagnetic substance layers 63 (67) for formingconductive parts for connection are located, are 60 μm (lateraldirection)×210 μm (vertical direction)×25 μm (depth), and the dimensionsof each of the recessed parts 64 c (68 c), at which the ferromagneticsubstance layers 63 a (67 a) for forming conductive parts fornon-connection are located, are 90 μm (lateral direction)×260 μm(vertical direction)×25 μm (depth), and the thickness of other portionsthan the recessed parts is 125 μm (the thickness of the recessed parts:100 μm).

(5) Production of Anisotropically Conductive Connector:

[Production of Anisotropically Conductive Connectors (A1) to (A10)]

The above-described frame plate, spacers and mold were used to formelastic anisotropically conductive films in the frame plate in thefollowing manner.

To and with 100 parts by mass of addition type liquid silicone rubberwere added and mixed 30 parts by mass of Conductive Particles (a).Thereafter, the resultant mixture was subjected to a defoaming treatmentby pressure reduction, thereby preparing a molding material for moldingelastic anisotropically conductive films.

In the above-described process, liquid silicone rubber of a two-packtype that the viscosity of Solution A is 250 Pa·s, the viscosity ofSolution B is 250 Pa·s, the compression set of a cured product thereofat 150° C. is 5%, the durometer A hardness of the cured product is 32,and the tear strength of the cured product is 25 kN/m was used as theaddition type liquid silicone rubber.

The properties of the addition type liquid silicone rubber weredetermined in the following manner.

(i) Viscosity of Addition Type Liquid Silicone Rubber:

A viscosity at 23±2° C. was measured by a Brookfield viscometer.

(ii) Compression Set of Cured Product of Silicone Rubber:

Solution A and Solution B in addition type liquid silicone rubber of thetwo-pack type were stirred and mixed in proportions that their amountsbecome equal. After this mixture was then poured into a mold andsubjected to a defoaming treatment by pressure reduction, a curingtreatment was conducted under conditions of 120° C. for 30 minutes,thereby producing a columnar body having a thickness of 12.7 mm and adiameter of 29 mm and composed of a cured product of the siliconerubber. The columnar body was post-cured under conditions of 200° C. for4 hours. The columnar body obtained in such a manner was used as aspecimen to measure its compression set at 150±20° C. in accordance withJIS K 6249.

(iii) Tear Strength of Cured Product of Silicone Rubber:

A curing treatment and post-curing of addition type liquid siliconerubber were conducted under the same conditions as in the item (ii),thereby producing a sheet having a thickness of 2.5 mm. A crescent typespecimen was prepared by punching from this sheet to measure its tearstrength at 23±2° C. in accordance with JIS K 6249.

(iv) Durometer A Hardness:

Five sheets produced in the same manner as in the item (iii) werestacked on one another, and the resultant laminate was used as aspecimen to measure its durometer A hardness at 23±2° C. in accordancewith JIS K 6249.

The molding material prepared was applied to the surfaces of the topforce and bottom force of the above-described mold by screen printing,thereby forming molding material layers in accordance with a patter ofelastic anisotropically conductive films to be formed, and the frameplate was superimposed in alignment on the molding surface of the bottomforce through the spacer for the side of the bottom force. Further, thetop force was superimposed in alignment on the frame plate through thespacer for the side of the top force.

The molding material layers formed between the top force and the bottomforce were subjected to a curing treatment under conditions of 100° C.for 1 hour while applying a magnetic field of 2 T to portions locatedbetween the ferromagnetic substance layers in a thickness-wise directionby electromagnets, thereby forming an elastic anisotropically conductivefilm in each of the anisotropically conductive film-arranging holes ofthe frame plate.

The elastic anisotropically conductive films thus obtained will bedescribed specifically. The total number of the elastic anisotropicallyconductive films in the anisotropically conductive connector is 393, andeach of the elastic anisotropically conductive films has dimensions of6,000 μm in the lateral direction and 1,200 μm in the verticaldirection.

A functional part in each of the elastic anisotropically conductivefilms has dimensions of 5,250 μm in the lateral direction and 210 μm inthe vertical direction, and an area of one surface thereof is 1.1025mm². Accordingly, a sum total S1 of areas of one surfaces of thefunctional parts of all the elastic anisotropically conductive films is433 mm², and a ratio S1/S2 of the sum total S1 of areas of one surfacesof the functional parts of all the elastic anisotropically conductivefilms to the area S2 of the surface of Wafer W1 for evaluation on a sidethat the electrodes to be inspected have been formed is 0.0138.

In the functional part in each of the elastic anisotropically conductivefilms, 50 conductive parts for connection are arranged at a pitch of 100μm in a line in the lateral direction. The dimensions of each of theconductive parts for connection are 120 μm in thickness, 40 μm in thelateral direction and 200 μm in the vertical direction. In thefunctional part, conductive parts for non-connection are arrangedbetween the conductive parts for connection located most outside in thelateral direction and the frame plate. The dimensions of each of theconductive parts for non-connection are 40 μm in the lateral directionand 200 μm in the vertical direction. The thickness of the insulatingpart in the functional part is 120 μm. A ratio (T2/T1) of the thicknessof the insulating part to the thickness of the conductive parts forconnection is 1. Accordingly, each of the functional parts is flat inboth surfaces and has an even thickness. Each of the functional parts isformed in such a manner that both surfaces thereof protrude from a partto be supported, and a projected height of the functional part is 25 μm.The overall thickness of the part to be supported in each of the elasticanisotropically conductive films is 70 μm, and the thickness of one ofthe forked portions is 10 μm.

Elastic anisotropically conductive films were respectively formed in 10frame plates in the above-described manner to produce a total of 10anisotropically conductive connectors. These anisotropically conductiveconnectors will hereinafter be referred to as Anisotropically ConductiveConnector (A1) to Anisotropically Conductive Connector (A10).

The parts to be supported and the insulating parts in the functionalparts of the elastic anisotropically conductive films were observed. Asa result, it was confirmed that the conductive particles are present inthe parts to be supported and that the conductive particles are scarcelypresent in the insulating parts in the functional parts.

[Production of Anisotropically Conductive Connectors (B1) to (B10)]

Ten anisotropically conductive connectors for comparison were producedin the same manner as in Anisotropically Conductive Connectors (A1) to(A10) except that the mold (K2) was used in place of the mold (K1).

The elastic anisotropically conductive films of the anisotropicallyconductive sheets thus obtained will be described specifically. Thetotal number of the elastic anisotropically conductive films in theanisotropically conductive connector is 393, and each of the elasticanisotropically conductive films has dimensions of 6,000 μm in thelateral direction and 1,200 μm in the vertical direction. Fiftyconductive parts for connection are arranged at a pitch of 100 μm in aline in the lateral direction. The dimensions of each of the conductiveparts for connection are 40 μm in the lateral direction, 200 μm in thevertical direction and 120 μm in thickness. Conductive parts fornon-connection are arranged between the conductive parts for connectionlocated most outside in the lateral direction and the -frame plate. Thedimensions of each of the conductive parts for non-connection are 40 μmin the lateral direction, 200 μm in the vertical direction and 120 μm inthickness. The projected height of the projected parts formed on theconductive parts for connection is 25 μm in each surface, and eachprojected part has dimensions of 60 μm in the lateral direction and 210μm in the vertical direction. The projected height of the projectedparts formed on the conductive parts for non-connection is 25 μm in eachsurface, and each projected part has dimensions of 90 μm in the lateraldirection and 260 μm in the vertical direction. Accordingly, a sum totalof areas of end surfaces of the projected parts in all the elasticanisotropically conductive films is 266 mm², and a ratio of the sumtotal of areas of end surfaces of the projected parts in all the elasticanisotropically conductive films to the area of the surface of Wafer W1for evaluation on a side that the electrodes to be inspected have beenformed is 0.0085. The thickness of the insulating part is 70 μm, and aratio (T2/T1) of the thickness of the insulating part to the thicknessof the conductive parts for connection is 0.58. The thickness (thicknessof one of the forked portions) of the part to be supported in each ofthe elastic anisotropically conductive films is 10 μm.

These anisotropically conductive connectors will hereinafter be referredto as Anisotropically Conductive Connector (B1) to AnisotropicallyConductive Connector (B10).

(6) Circuit Board for Inspection:

Alumina ceramic (coefficient of linear thermal expansion: 4.8×10⁻⁶/K)was used as a base material to produce a circuit board for inspection,in which inspection electrodes had been formed in accordance with apattern corresponding to the pattern of the electrodes to be inspectedin Wafer W1 for evaluation. This circuit board for inspection isrectangular having dimensions of 30 cm×30 cm as a whole and. Theinspection electrodes thereof each have dimensions of 60 μm in thelateral direction and 200 μm in the vertical direction. This circuitboard for inspection will hereinafter be referred to as “Circuit Board Tfor inspection”.

(7) Sheet-Like Connector:

A laminate material obtained by laminating a copper layer having athickness of 15 μm on one surface of an insulating sheet formed ofpolyimide and having a thickness of 20 μm was provided, and theinsulating sheet in this laminate material was subjected to lasermachining, thereby forming 19,650 through-holes each extending throughin a thickness-wise direction of the insulating sheet and having adiameter of 30 μm in the insulating sheet in accordance with a patterncorresponding to the pattern of the electrodes to be inspected in WaferW1 for evaluation. This laminate material was then subjected tophotolithography and a nickel plating treatment, thereby forming shortcircuit parts integrally connected to the copper layer in thethrough-holes in the insulating sheet, and at the same time, formingprojected front-surface electrode parts integrally connected to therespective short circuit parts on the front surface of the insulatingsheet. The diameter of each of the front-surface electrode parts was 40μm, and the height from the surface of the insulating sheet was 20 μm.Thereafter, the copper layer of the laminate material was subjected to aphoto-etching treatment to remove a part thereof, thereby formingrectangular back-surface electrode parts each having dimensions of 60μm×210 μm. Further, the front-surface electrode parts and back-surfaceelectrode parts were subjected to a gold plating treatment, therebyforming electrode structures, thus producing a sheet-like connector.This sheet-like connector will hereinafter be referred to as “Sheet-likeConnector M”.

(8) Initial Properties of Elastic Anisotropically Conductive Film:

The initial properties of elastic anisotropically conductive films ineach of Anisotropically Conductive Connectors (A1) to (A10) andAnisotropically Conductive Connectors (B1) to (B10) were determined inthe following manner.

An anisotropically conductive connector was arranged on Circuit Board Tfor inspection in alignment in such a manner that the conductive partsfor connection thereof are located on the respective inspectionelectrodes of Circuit Board T for inspection, and a peripheral portionof the anisotropically conductive connector was bonded to Circuit BoardT for inspection with RTV silicone rubber to produce a probe member.This probe member was then fixed to a pressurizing plate, and Wafer W1for evaluation was mounted on a wafer mounting table. A CCD cameracapable of viewing both upper and lower directions was advanced betweenthe probe member and Wafer W1 for evaluation, and alignment of Wafer W1for evaluation was conducted to the probe member in accordance with theimages of this CCD camera in such a manner that the conductive parts forconnection of the anisotropically conductive connector are respectivelylocated right over the electrodes to be inspected of Wafer W1 forevaluation. The CCD camera was then removed from between the probemember and Wafer W1 for evaluation, and the probe member was pressurizeddownward under a load of 58.95 kg (load applied to every conductive partfor connection: 3 g on the average), thereby bringing the elasticanisotropically conductive films of the anisotropically conductiveconnector into contact under pressure with Wafer W1 for evaluation. Anelectric resistance between each of the 19,650 inspection electrodes inCircuit Board T for evaluation and the lead electrode of Wafer W1 forevaluation was successively measured at room temperature (25° C.) as anelectric resistance (hereinafter referred to as “conduction resistance”)in the conductive part for connection to calculate out a proportion ofconductive parts for connection that the conduction resistance was lowerthan 1 Ω.

Wafer W2 for evaluation was mounted in place of Wafer W1 for evaluationon the wafer mounting table, a CCD camera capable of viewing both upperand lower directions, was advanced between the probe member and Wafer W2for evaluation, and alignment of Wafer W2 for evaluation was conductedto the probe member in accordance with the images of this CCD camera insuch a manner that the conductive parts for connection of theanisotropically conductive connector are respectively located right overthe electrodes to be inspected of Wafer W2 for evaluation. The CCDcamera was then removed from between the probe member and Wafer W2 forevaluation, and the probe member was pressurized downward under a loadof 58.95 kg (load applied to every conductive part for connection: 3 gon the average), thereby bringing the elastic anisotropically conductivefilms of the anisotropically conductive connector into contact underpressure with Wafer W2 for evaluation. An electric resistance betweenadjoining 2 inspection electrodes in Circuit Board T for evaluation wassuccessively measured at room temperature (25° C.) as an electricresistance (hereinafter referred to as “insulation resistance”) betweenadjoining 2 conductive parts for connection (hereinafter referred to as“pairs of conductive parts”) to calculate out a proportion of pairs ofconductive parts that the insulation resistance was 10 MΩ or higher.

The results are shown in Table 1. TABLE 1 Proportion of Proportion ofconductive parts pairs of conduc- for connection tive parts that thatthe conduc- the insulation tion resistance resistance was was lower than10 MΩ or 1 Ω (%) higher (%) Examples Anisotropically 100 0 ConductiveConnector (A1) Anisotropically 100 0 Conductive Connector (A2)Anisotropically 100 0 Conductive Connector (A3) Anisotropically 100 0Conductive Connector (A4) Anisotropically 100 0 Conductive Connector(A5) Anisotropically 100 0 Conductive Connector (A6) Anisotropically 1000 Conductive Connector (A7) Anisotropically 100 0 Conductive Connector(A8) Anisotropically 100 0 Conductive Connector (A9) Anisotropically 1000 Conductive Connector (A10) Comparative Anisotropically 100 0 ExamplesConductive Connector (B1) Anisotropically 100 0 Conductive Connector(B2) Anisotropically 100 0 Conductive Connector (B3) Anisotropically 1000 Conductive Connector (B4) Anisotropically 100 0 Conductive Connector(B5) Anisotropically 100 0 Conductive Connector (B6) Anisotropically 1000.1 Conductive Connector (B7) Anisotropically 100 0.1 ConductiveConnector (B8) Anisotropically 99.5 0.2 Conductive Connector (B9)Anisotropically 99.3 0.4 Conductive Connector (B10)(9) Test 1:

A durability test under a high-temperature environment was conducted asto Anisotropically Conductive Connector (A1), Anisotropically ConductiveConnector (A2), Anisotropically Conductive Connector (B1) andAnisotropically Conductive Connector (B2) in the following manner.

An anisotropically conductive connector was arranged on Circuit Board Tfor inspection in alignment in such a manner that the conductive partsfor connection thereof are located on the respective inspectionelectrodes of Circuit Board T for inspection, and a peripheral portionof the anisotropically conductive connector was bonded to Circuit BoardT for inspection with RTV silicone rubber to produce a probe member.This probe member was then fixed to a pressurizing plate, and Wafer W4for test was mounted on a wafer mounting table equipped with an electricheater. A CCD camera capable of viewing both upper and lower directionswas advanced between the probe member and Wafer W4 for test, andalignment of Wafer W4 for test was conducted to the probe member inaccordance with the images of this CCD camera in such a manner that theconductive parts for connection of the anisotropically conductiveconnector are respectively located right over the electrodes to beinspected of Wafer W4 for test. The CCD camera was then removed frombetween the probe member and Wafer W4 for test, and the probe member waspressurized downward under a load of 158 kg (load applied to everyconductive part for connection: 8 g on the average), thereby bringingthe elastic anisotropically conductive films of the anisotropicallyconductive connector into contact under pressure with Wafer W4 for test.The wafer mounting table was then heated to 125° C. After thetemperature of the wafer mounting table became stable, an electricresistance between 2 inspection electrodes electrically connected toeach other through the anisotropically conductive connector and Wafer W4for test among the 19,650 inspection electrodes in Circuit Board T forinspection was successively measured to record a half value of theelectric resistance value measured as a conduction resistance of theconductive part for connection in the anisotropically conductiveconnector, thereby counting the number of conductive parts forconnection that the conduction resistance was 1 Ω or higher. Thereafter,the wafer mounting table was left to stand for 1 hour in this state andthen cooled to room temperature. Thereafter, the pressure against theprobe member was released.

The above-described process was regarded as a cycle, and the cycle wascontinuously repeated 500 times in total.

In the above-described test, those that the conduction resistance of theconductive part for connection is 1 Ω or higher are difficult to beactually used in electrical inspection of integrated circuits formed ona wafer.

The results are shown in Table 2.

(10) Test 2:

A durability test under a high-temperature environment was conducted asto Anisotropically Conductive Connector (A3), Anisotropically ConductiveConnector (A4), Anisotropically Conductive Connector (B3) andAnisotropically Conductive Connector (B4) in the following manner.

An anisotropically conductive connector was arranged on Circuit Board Tfor inspection in alignment in such a manner that the conductive partsfor connection thereof are located on the respective inspectionelectrodes of Circuit Board T for inspection, a peripheral portion ofthe anisotropically conductive connector was bonded to Circuit Board Tfor inspection with RTV silicone rubber, Sheet-like Probe M was arrangedon this anisotropically conductive connector in alignment in such amanner that the back-surface electrode parts thereof are located on therespective conductive parts for connection of the anisotropicallyconductive connector, and a peripheral portion of Sheet-like Connector Mwas bonded to Circuit Board T for inspection with RTV silicone rubber toproduce a probe member. This probe member was then fixed to apressurizing plate, and Wafer W3 for test was mounted on a wafermounting table equipped with an electric heater. A CCD camera capable ofviewing both upper and lower directions was advanced between the probemember and Wafer W3 for test, and alignment of Wafer W3 for test wasconducted to the probe member in accordance with the images of this CCDcamera in such a manner that the front-surface electrode parts of thesheet-like connector are respectively located right over the electrodesto be inspected of Wafer W3 for test. The CCD camera was then removedfrom between the probe member and Wafer W3 for test, and the probemember was pressurized downward under a load of 158 kg (load applied toevery conductive part for connection: 8 g on the average), therebybringing the elastic anisotropically conductive films of theanisotropically conductive connector into contact under pressure withWafer W4 for test. The wafer mounting table was then heated to 125° C.After the temperature of the wafer mounting table became stable, anelectric resistance between 2 inspection electrodes electricallyconnected to each other through the anisotropically conductiveconnector, Sheet-like Connector M and Wafer W3 for test among the 19,650inspection electrodes in Circuit Board T for inspection was successivelymeasured to record a conduction resistance of the conductive part forconnection in the anisotropically conductive connector, thereby countingthe number of conductive parts for connection that the conductionresistance was 1 Ω or higher. Thereafter, the wafer mounting table wasleft to stand for 1 hour in this state and then cooled to roomtemperature. Thereafter, the pressure against the probe member wasreleased.

The above-described process was regarded as a cycle, and the cycle wascontinuously repeated 500 times in total.

In the above-described test, those that the conduction resistance of theconductive part for connection is 1 Ω or higher are difficult to beactually used in electrical inspection of integrated circuits formed ona wafer.

The results are shown in Table 3. Number of conductive parts forconnection that the conduction resistance is 1Ω or higher (counts)Anisotropically Number of cycles conductive connector 1 20 50 100 200300 400 500 Examples (A1) 0 0 0 0 0 0 0 22 (A2) 0 0 0 0 0 0 4 28Comparative (B1) 0 0 0 0 0 6 36 122 Examples (B2) 0 0 0 0 4 18 52 214

Number of conductive parts for connection that the conduction resistanceis 1Ω or higher (counts) Anisotropically Number of cycles conductiveconnector 1 20 50 100 200 300 400 500 Examples (A3) 0 0 0 0 0 0 0 0 (A4)0 0 0 0 0 0 0 0 Comparative (B3) 0 0 0 0 0 0 8 34 Examples (B4) 0 0 0 00 0 4 44

As apparent from the results shown in Tables 1 to 3, it was confirmedthat according to the anisotropically conductive connectors related toExamples, good conductivity is achieved on the conductive parts forconnection in the elastic anisotropically conductive films even when thepitch of the conductive parts for connection is small, and moreover thata good electrically connected state is stably retained even byenvironmental changes such as thermal hysteresis by temperature change,and good conductivity is retained over a long period of time even whenthey are used repeatedly under a high temperature environment. It wasalso confirmed that according to the anisotropically conductiveconnectors related to Examples, high durability in repeated use isattained even when a wafer, which is an object of inspection, has agreat number of electrodes to be inspected, and these electrodes to beinspected are projected electrodes.

1. An anisotropically conductive connector comprising elasticanisotropically conductive films each having a functional part, in whicha plurality of conductive parts for connection containing conductiveparticles and extending in a thickness-wise direction of the film havebeen arranged in a state mutually insulated by an insulating part,wherein assuming that a thickness of the conductive parts for connectionin the functional part of the elastic anisotropically conductive film isT1 and a thickness of the insulating part in the functional part is T2,a ratio (T2/T1) is at least 0.9.
 2. An anisotropically conductiveconnector suitable for use in conducting electrical inspection of eachof a plurality of integrated circuits formed on a wafer in a state ofthe wafer, which comprises: a frame, plate, in which a plurality ofanisotropically conductive film-arranging holes each extending throughin a thickness-wise direction of the frame plate have been formedcorresponding to electrode regions, in which electrodes to be inspectedhave been arranged, in all or part of the integrated circuits formed onthe wafer, which is an object of inspection, and a plurality of elasticanisotropically conductive films arranged in the respectiveanisotropically conductive film-arranging holes in this frame plate andeach supported by the peripheral part about the anisotropicallyconductive film-arranging hole, wherein each of the elasticanisotropically conductive films is equipped with a functional parthaving a plurality of conductive parts for connection arrangedcorresponding to the electrodes to be inspected in the integratedcircuits formed on the wafer, which is the object of inspection,containing conductive particles exhibiting magnetism at a high densityand extending in a thickness-wise direction of the film, and aninsulating part mutually insulating these conductive parts forconnection, and wherein assuming that a thickness of the conductiveparts for connection in the functional part of the elasticanisotropically conductive film is T1 and a thickness of the insulatingpart in the functional part is T2, a ratio (T2/T1) is at least 0.9. 3.The anisotropically conductive connector according to claim 2, whereinat least one surface of the functional part in each of the elasticanisotropically conductive films is flat.
 4. The anisotropicallyconductive connector according to claim 3, wherein said at least oneflat surface of the functional part in each of the elasticanisotropically conductive films is formed so as to project from anyother portion, and wherein assuming that a sum total of areas of onesurfaces of the functional parts of all the elastic anisotropicallyconductive films is S1, and an area of a surface of the wafer, which isthe object of inspection, on a side that the electrodes to be inspectedhave been formed, is S2, a ratio S1/S2 is 0.001 to 0.3.
 5. Theanisotropically conductive connector according to claim 4, wherein thecoefficient of linear thermal expansion of the frame plate is at most3×10⁻⁵/K.
 6. A probe member suitable for use in conducting electricalinspection of each of a plurality of integrated circuits formed on awafer in a state of the wafer, which comprises: a circuit board forinspection, on the surface of which inspection electrodes have beenformed in accordance with a pattern corresponding to a pattern ofelectrodes to be inspected of the integrated circuits formed on thewafer, which is an object of inspection, and the anisotropicallyconductive connector according to claim 5, which is arranged on thesurface of the circuit board for inspection.
 7. The probe memberaccording to claim 6, wherein the coefficient of linear thermalexpansion of the frame plate in the anisotropically conductive connectoris at most 3×10⁻⁵/K, and the coefficient of linear thermal expansion ofa base material making up the circuit board for inspection is at most3×10⁻⁵/K.
 8. The probe member according to claim 6, wherein a sheet-likeconnector composed of an insulating sheet and a plurality of electrodestructures each extending through the insulating sheet in athickness-wise direction thereof and arranged in accordance with apattern corresponding to the pattern of the electrodes to be inspectedis arranged on the anisotropically conductive connector.
 9. A waferinspection apparatus for conducting electrical inspection of each of aplurality of integrated circuits formed on a wafer in a state of thewafer, which comprises the probe member according to claim 6, whereinelectrical connection to the integrated circuits formed on the wafer,which is an object of inspection, is achieved through the probe member.10. A wafer inspection method comprising a step of electricallyconnecting each of a plurality of integrated circuits formed on a waferto a tester through the probe member according to claim 6 to performelectrical inspection of the integrated circuits formed on the wafer.11. A wafer inspection apparatus for conducting electrical inspection ofeach of a plurality of integrated circuits formed on a wafer in a stateof the wafer, which comprises the probe member according to claim 7,wherein electrical connection to the integrated circuits formed on thewafer, which is an object of inspection, is achieved through the probemember.
 12. A wafer inspection apparatus for conducting electricalinspection of each of a plurality of integrated circuits formed on awafer in a state of the wafer, which comprises the probe memberaccording to claim 8, wherein electrical connection to the integratedcircuits formed on the wafer, which is an object of inspection, isachieved through the probe member.
 13. A wafer inspection methodcomprising a step of electrically connecting each of a plurality ofintegrated circuits formed on a wafer to a tester through the probemember according to claim 7 to perform electrical inspection of theintegrated circuits formed on the wafer.
 14. A wafer inspection methodcomprising a step of electrically connecting each of a plurality ofintegrated circuits formed on a wafer to a tester through the probemember according to claim 8 to perform electrical inspection of theintegrated circuits formed on the wafer.